Are there any guys on this forum that are in there 40s and beyond that are actually getting women in there 20s and lower 30s without having to pay for it?
If that's all you're worried about...yes of course. Since I turned 40 dated almost exclusively girls in their 20s, some early 30s. In fact, I spend very little "dating" time with women in my age bracket.
The point of improving yourself, even though death stalks us all, is for the sheer enjoyment of it. Why do I read a book, or watch a film, or lift weights? I like it - I like the process, the moment, and I like the results. A better me. Of course, one day I'll die. What will happen with all that stored memory and knowledge? I don't know. But I'm going to enjoy it while I'm here. I imagine everything I learn and experience gets sent back out into the universe, somehow.
As for career changes, if it's what you truly desire, go for it. No point in idling your time unsatisfied. At 42 I quit my job and went back to school in another country. I'm living better than I could have dreamed because I followed my heart. You just have to assess whether you're pursuing what you want, or just change for change's sake.
Of course, there are some adjustments to make. It's harder for me to burn body fat or build muscle. Still, I persist. On the other hand, I have so much experience with women that they're like child's play to me. My 25 year old self would be impressed.
If you're having an existential crisis, think about all the humanity that's been wasted. Babies stillborn, children dying of cancer. Teens committing suicide or dying in car wrecks. You don't think they'd trade places with you? Imagine just one ship sailing the Mediterranean in the year 1450. You think the oar-rowers got paid? They were harvested, worked like dogs, tossed overboard, and replaced. Now multiply that ship by 100,000 and you'll have maybe some idea of the lives that have gone to waste over the centuries, or at least never got the chance to mull whether to study engineering or bang a 20 year old.
There's a Bob Dylan song called "My Back Pages" where he sings, "I was so much older then / I'm younger than that now." It rings true for me, I take things way less seriously than I used to. Youth is often wasted on the young, remember that.