I didn’t finish all the responses so maybe someone has addressed this, apologies if it has.
I am also a grown a$$ adult who is newer to showing, although I have been riding, owning, caring for and training for many decades. Anyway, I love horse showing. I also know I’m not heading towards the Olympics or any big time year end ammy award. I’m just trying to put in some decent rounds at the 1.0m and not embarrass myself. All that is to say, one of the very best parts of showing, is going with the ammy crew and winning/losing/succeeding/failing/suffering and celebrating together. We cheer each other on, we bring fancy snacks to eat in the tent, we bring wine to celebrate or drown sorrows. We spend the early predawn together feeding and handwalking. We borrow show coats and blue shampoo and fly spray. We sprint across show grounds with a forgotten martingale.
It might be worth it to find a group of like minded humans, they could be fellow adults or even juniors. But it really enhances the showing experience and justifies the insane expenses. Personally, it wouldn’t be worth it to show alone for me (as always, to each their own). But showing with my barn crew feels 100% worth the money