Biotech R&D — there's still many thousands of diseases that have yet to be 100% cured and while a nice dent might be made, that number will not be going to zero in the next 50-100 years. And even when it eventually does, there will always be enhance-based biotech research beyond that. Also, there's pretty decent upward mobility in Biotech and, when you're eventually ready to start your own company in the second half of your career (or earlier, if you have exceptional go'getitude), fundraising is pretty straightforward compared to other industries — product market fit, founder personality, marketing costs — none of it matters, they really only want to see your preclinical data (and depending on the investor, maybe the total addressable market). Even new companies going after relatively small orphan diseases get funded with good data, knowing they can charge more for these therapies to offset the smaller population, and that insurance companies will bare the cost.