We can’t eliminate all suffering and harm, so we shouldn’t even try reducing it? Perfect is the enemy of good. For many if not most vegans, it’s about minimizing harm. Many are motivated by ecological concern as well.
Some insects die on my car’s grill when I’m driving. I still go to work every day while calling myself vegan. Literally the only non-hypocritical action would be to kill myself. Forgive me if I don’t.
Also consider a healthcare career. As a teenager, I wanted to do computer science/engineering, and sometimes I do wish I had stayed on that track. But now, as a nurse, I could get a job in any state in the US by tomorrow. I dare you to try to find a hospital that doesn’t have open nursing positions. Even when the economy goes down, people still get sick. Even if society collapses, the knowledge/skills will be useful.
And if you don’t want to change diapers or deal with blood, there are still options; I’m in psychiatry and rarely have to deal with either.