I honestly don't think one cast is better than the other. And if it were, I'd honestly say I like the younger cast better overall.
As some have pointed out however, I do think it is a bit hard for Audiences to "care" when it sort of switches back and forth. You need to be able to invest. We know and love these characters so to us it matters less who plays them as long as they do a great job, but non comic readers are probably a bit confused and gave up.
Also, I think 9 times out of 10 prequels just aren't as popular. Especially after Star Wars essentially soiled the idea forever. Even Star Trek now has fans wondering if it was a good idea, yet back in 2009 most people loved it. A prequel is fine, a series of them just runs out of steam. Even with the new timeline, it can still feel like the series isn't moving forward
So I get why people want a true sequel. But real life business decisions make that tricky. I personally would love to have both old and new at the same time, but for above reasons, that would be messy.