[antasvara]

Is it viable? Probably. Much of the world manages to get jobs without prepping on their free time. With 8 years of experience, it's likely that you'll be able to find at least some kind of job, even if it isn't an ideal fit.

Does it slow your career advancement? Yes. Does it decrease your likelihood of finding higher level jobs? Also yes.

Ultimately it's up to you how you value your free time. There's clear value in skill development and interview prep in that it helps you improve your chances of getting a better job.