Those are inherent to online distribution, and have been discussed to death in other forums.
It really is not a problem, though you may not like that. It is the nature of distribution. The options are to have curated, gated, and limited product selection, OR to have unlimited selection. Both have their merits.
In the physical marketplace there are barriers to the market. Stores have limited room so they curate the content. They tend to choose only from among major publishers, and those publishers curate their content. All these steps cost money, which is another barrier to the market. Some online communities are like this as well. As a result, the products that are available to customers are highly vetted. They include both the best products and the cheap-yet-okay products, and remove all the garbage that you point out. Real people reviewed them and decided they were good.
Most online distributors accept any product. Anyone can get on Amazon, or Google Play, or the Apple App Store, there are minimal hoops. Steam used to have some barriers, but they are trivial to get over. On the positive side if you are a developer, it is very easy to get your game out to the masses. On the negative side if you are a consumer, there is an enormous amount of trash and even harmful material out there. Products are only reviewed by real people if they start receiving complaints, and by then some damage has been done.
If you want curated products then use portals that are curated. But you'll live with the consequences that you'll only get the the mainstream stuff that is mass-market popular or that has money to spread. On the flip side, if you want all the options and obscure stuff use the non-gated communities, but remember buyer beware, there is a lot of bad stuff out there.
Neither type of marketplace is in error, neither type is wrong. Some people love the flea market, a place in the physical world where anybody can sell goods, new and used, amazing and trash. Other people hate the environment and only shop where there are return policies and legal protections for buyers.
You have made it clear: You want the vetted market, the place with gatekeepers, the place where the bad actors are blocked from attendance. There is nothing wrong with that. But don't discount that many people prefer the other kind of marketplace, the one where anybody can publish, and where there are many amazing gems that have limited appeal, which would never make it past the traditional gatekeepers.
If you want Steam to do more vetting, then talk to steam and join the discussions they have on the matter. But don't advocate to have the other markets shut down. We need all kinds, they serve different groups.