itch.io

Good luck with that.

Others have tried, but since support just never replies and the whole support system for developers seems fairly terrible, some have given up and no longer sell their game on itch. E.g.:
https://tyronx.itch.io/vintage-story

It really seems like there is great need to bring someone professional into the fold on the itch project who can handle the business side.

What kind of abuse are you talking about? Review bombing? As long as the developer is given means to deal with non-game-related reviews, I don't see the problem. Yes, that might need staff to take a look at some cases, but frankly that's what you pay percentages for.

And what kind of advantage you are talking about, I have no idea. If at all, currently the developer has a strong advantage over the consumer on itch.io as no user reviews are prominently shown, and the only thing that (sometimes) is shown is an average score, which is frankly entirely useless.
A game being rated 60% on average tells you nothing. Could be a very divisive game, meaning you might still love it. Could be a very average game, meaning you might still love it. Could be a very buggy game that you might love once fixed. Only extreme ratings (<30%, >90%) convey any useful information with some certainty (this game is bad/good at what it does).
Written user reviews are needed for users to form an informed opinion. And itch.io already lets users write them, so why not show them more prominently?

Fully agree with this.
The rating stuff at the moment is just very weak. Ratings of a game should be one of the first things you see of a game, along with the description. Not hidden behind some menu. That includes the average score as well as recent "reviews". Just take a look at how Steam & GOG do it. Something along those lines should be perfectly doable.

This has been a long requested feature: https://github.com/itchio/itch.io/issues/738
Which, very unfortunately, is still not implemented.

I feel like this is one of itch's biggest problems, at the moment, and will probably deter many users.
No matter what kinds of games you like or don't like, as soon as you browse games you'll be plastered with genres you have no interest in. So at the very least, there should be an easy way to exclude genres (and other identifiers if desired) for good.