I used to be an employee that would kill themselves for even minimum wage.
I think being a hard worker regardless of reward is an honorable trait, but keeping that up for decades is difficult. Naturally I am very loyal and agreeable. I like to solve raw engineering problems, but also social ones. I find a way to adapt to pretty much anything and anyone.
This almost always ends with my employer exploiting me.
Recently I've switched it up. I focus for a solid 2-4 hours a day on my tasks, and I use the remaining time for learning. It keeps my mind moving and keeps burnout at bay. Even average engineers like myself can optimize their workflow endlessly. You have a few choices at that point. You can give your surplus labor back to your employer in exchange for raises, bonuses, promotions etc. You can take back those hours to improve your WLB. You can reinvest those hours into learning that benefits your current employer, but more importantly, makes you more attractive in the job market.
Right now I find myself consistently choosing the third option. Not because I'm focused on maximizing my earnings, but because it is the most fulfilling and enjoyable option for me.