It's worked for me for the past 10 years, part-time in engineering at Google, Makani, and Elemeno Health. Not wanting or being able to work a lot of hours doesn't necessarily mean not being flexible on hours. I've known a number of other part-time people at e.g. Google, and they were generally people I'd trust to get stuff done. Often they're time-management masters, due to necessity.

Sure, there's more overhead per working hour. But there's also more mulling-things-over-in-the-shower time per working hour, so for creative work, one can be a lot more effective than you'd think. I also get more sleep and do all my appointments and errands in non-working hours, which improves my duty cycle and performance.