Procreation (kinda self-defining isn’t it?)

I have absolutely no idea why one would choose to procreate at age 50+. I was 32 when my youngest was born and I'm so thankful that I don't have any truly young children while I'm in my 50s. Procreation at older ages is both foolish and selfish.

Enjoyment

What if it's not enjoyable? For many it's not even a question of mental health. It's truly just that life sucks and there is no practical expectation that it's going to change. We should quit vilifying such people. Either change the system so they can have enjoyment or let them end it instead of adding to their misery for saying that they should seek help that they can't even access. None of us should be in full on enjoyment mode as long as we continue to allow the system to exist that creates this situation for so many.

no one over 50 has anything to offer the next generation (wisdom?)

While wisdom is something that more people should listen to, age alone is no determination of whether someone is wise or just an old fool. As such, it's really not a particularly valid answer to the original question.

I have concern for you. If you need someone to explain this, well, I pity you.

glass houses, stones, blah, blah...