Depends the sacrifices you are willing to make and what you want.
I earn 300K CAD between the jobs plus a pension. Let's call it 230K USD. I have three years of experience. I live in a low cost city in Canada as all my jobs are remote. I suppose it depends on whether you view this as a pro or a con, but my earnings are virtually all cash (some 20K in stock in total), so I am not taking a beating with the current markets. I work about 5-6 hours a day, mostly by being willing to volunteer for stuff that others hate or consider useless careerwise internally (I will happily be the support dev for example, despite that meaning I show far fewer achievements come review time).
Being support dev (monitor Sentry and resolve all the bugs) works because I never join teams with core production responsibilities, so support is never urgent. Say that you are with Netflix. You want to be on the analytics team, not the streaming team. But other devs still hate it, so nobody will question taking a day to answer a question as everyone else doesn't even want to think about it. I went to the extreme and stretched out a config issue for three weeks. My manager and the other members of my team wrote me letters of praise and the skip manager had a meeting to praise me over handling it. Niche knowledge can be quite powerful. Debugging is also a skill in itself. I have also survived several layoffs, so plenty of opportunities to get rid of me.
Pick your teams very strategically. The equivalent of the streaming team at my Job 1 has a horrendous work schedule and 3AM on-call. I have never worked a job with on-call.
Also, choose to work on tools for work, a.k.a things that nobody will complain about over the weekend.
> Do you ever get raises?
I don't generally stick around at any org long enough to get raises, as the job hops have led to huge increases. I was earning 65K two years ago and that was two jobs ago. But I am told that I will be getting at least 8% this year at Job 1. Job 2 has a union ratchet, so performance hardly matters. Job 3, probably not, as they are stingy in every other way (but you can disappear for days and have it not be a big deal).
I personally view raises as kind of a scam. Another dev on one of my teams is brilliant and highly productive, far more so than I am. She didn't get a raise with her promo. I am getting a raise for existing at Job 1. Be friendly, be funny, and you can get away with a lot.
> Do these jobs actually pay over 33% of the best job you could get?
Given the sacrifices I am willing/unwilling to make, yes. If I were willing to make other sacrifices like relocating or working harder, no. I also cannot leetcode that well. If you work for Google, you are beating this strategy.
> Would it be more stressful to juggle this kind of thing than the level of stress at a normal job you're invested in?
I find it less stressful as you just stop caring about all the little games. You stop caring about whether your standup report is meaningful or shows sufficient work. You stop caring about showing initiative. You stop caring about going the extra mile, or about leaving a bug unfixed over the weekend. You find yourself awash in so much cash that losing your job for years wouldn't matter. You don't worry about delivering, as deadlines are meaningless.
Obviously don't blow high profile things, but as long as you deliver the bigger noticeable stuff to a decent standard (and bugs are one area to do that), all is well.
At least in my case, I can coast to retirement within a year and will have a fully paid off upper middle class house before I am 30. That is also a huge stress reliever, as (contingent on responsible spending and prudent investing) I only need to keep up the high salary for 4-5 years.