Is ZZZ Worth It?

I'm thinking about quitting HSR. I wanted to invest in a certain character's team first because people say vertical investment is better and I haven't pulled for the new meta mechanic yet even though I want to get a character of that mechanic. But it's just shilling + the usual HP inflation nowadays, and I can't properly clear content while I'm trying to vertically invest.

These are the main questions I want to ask, and please give extra information about ZZZ if there's anything I'm missing.

1. Are there difficulties in clearing endgame? If no, how easy it is to get the max score?

2. Is there bad powercreeping?

3. Enemy HP inflation?

4. Is it easy to grind for polychromes?

P.S. I don't know if I should post this on HSR or ZZZ subreddit, so I'm posting this on both.