Many of us have more money than time, and would be happy to trade some money for time. Companies should let us do this.
When you're done with one project and haven't started the next one, or are looking for a team to join, you should be entitled to take a quarter or two off. Not as an exception, or as a benefit given to star performers (which most of us aren't, by definition), but to everyone.
This can be unpaid leave. Further, the company can deduct the cost of medical and life insurance from your salary. That way, there's no cost to the company.
Sabbaticals of this kind have many benefits.
The first is work-life balance — spending time with your family or friends or pursuing your hobbies, or developing new ones.
The second is professional development, like a developer choosing to build a Mac app and sell it . Many of us have certain skills we want to develop, or a direction we want to take our career in. These often doesn't match opportunities available at work. Sabbaticals provide such an opportunity, to focus on our own goals rather than the OKR-of-the-quarter. That way, we can progress in our careers in ways that are important to us in the long-term. And these skills may later turn out to be useful to the company as well, say if they need someone to build a Mac app, in this example.
The third advantage of sabbaticals is avoiding burnout if you have an unfulfilling job, which most jobs are, even at some of the best employers. If you've given up on finding work aligned with your interests and passions and are just in it for the money, you may want to take a quarter or two off once every year or two to unwind and find meaning in interests outside work, like hobbies.
The fourth advantage of sabbaticals applies to people who've finished one project but haven't found another that is aligned with their interests. They can take a sabbatical, come back later and hopefully find such a project, and thereby remain with the company, rather than quitting. This was part of the reason I left my last job. Before I left, I asked for a two-quarter unpaid leave, but HR told me they don't give such a long leave, and in any case, I need to find a team to join before I go on leave. This bureaucratic answer defeats the very purpose of asking for the leave.
A sabbatical is similar to working part-time, in that you work fewer hours over the course of a job, and make less money. But you take that time off in big chunks of a quarter or two, rather than a day or two a week. That lets you do things you can't otherwise do, like travel. Or work on a personal project with less time lost to context switches. That goes for relaxing as well — often, by the time my mind fully relaxes from the busy work week, it's Sunday evening, and I don't have much time to enjoy before I have to be back in the office. So, while a sabbatical is conceptually similar to working part-time in that you work a little less and get paid a little less, in practice, it lets you take on more projects or hobbies.
Another advantage of a sabbatical over working part-time is that a company needs more people working on a project if they're part-time. This increases coordination costs, and fixed overheads. If you have to attend a team meeting for an hour a week, that's a bigger percentage of your time lost if you're working part-time. That means a person who works four days a week adds less than 80% value of a person working five. The company loses, and so does the employee.
Sabbaticals have one advantage for the company over other ways of having a better a better work-life balance, like part-time, or more days of vacation per year . Which is that sabbaticals don't delay the delivery of the project you're working on. I worked for a company that officially let employees work four days a week for 80% the pay. When I decided to take this option, a manager told me that he'd instead want to hire someone else working five days a week to deliver his project quicker. The same problem occurs if you want more days of vacation every year. Whereas taking sabbaticals in between projects doesn't impact the delivery of any particular project and so has less cost to the company.
This also represents a novel way of thinking about a job — instead of working continously for many years, look at your career as a series of projects with breaks in between. But this is not the same as freelancing. Or the so-called gig economy, like driving for Uber, which I'll categorise under the umbrella of freelancing, for the purpose of this post. Unlike freelancing, a full-time job with sabbaticals still pays a fixed monthly income. You have control over your income, by delaying a sabbatical if you can't afford it right now. In that sense, a full-time job with breaks falls between a traditional full-time job and freelancing. It's more flexible than a traditional job, but less flexible than freelancing. In return for losing some flexibility, you gain some safety, that of a steady income. A job with sabbaticals may be the right answer for many people who currently work at a job without sabbaticals. It's a step up in in flexibility, with little downside — don't take any sabbaticals if you don't want to or can't afford to. There's little downside to the company as well, since it's an unpaid leave, and it doesn't delay their projects.
Everyone benefits. More companies should offer sabbaticals. Enough that sabbaticals will be viewed as the next step in flexibility, like flexitime is compared to having to turn up at your desk and start coding by 9:00. If enough companies offer sabbaticals, companies that don't will start to be viewed as backward and inflexible. I can't wait for that to happen.
 This will also require companies to do away with onerous, grasping clauses in their employment agreements that lay claim to software one builds in one's own time without using company resources.
 I initially also listed a job that doesn't regularly make you work longer hours, but that should be the norm for all jobs, not something extra a company grants you out of their generosity. I give the company 40 hours of my time every week in exchange for some money. The company isn't automatically entitled to more of my time just because the deadline-of-the-month wasn't hit. That's their problem, not mine. We need governments or unions to step in and safeguard employees' rights, like in Europe. Working extra should be entirely your choice, without pressure or penalty from the company, that you make for some benefit like overtime pay or quicker promotion.