At some point if I transition to FAANG/something closer to my ideal, I'd definitely like to grind so I doubt I would have time for much outside of work.

If you want to make that transition, you're gonna be competing with people who work hard from day 1, and not just when it's time to make the jump to FAANG. It's really hard to beat people who put in the time for their craft, in the long-run

You don't have to work at a "name-brand" company to have an enjoyable, challenging and rewarding career. Most people don't. Ignore everyone who tells you that the name of the company you work for, or length of your title are what matter in life

    How does WLB change over time for most people?

I think for a lot of people, they tend to have the fewest commitments immediately out of college. Life responsibilities tend to pile up as you get older, which makes it nice to have "banked" a bunch of good will, hard work, and connections from earlier in your career