What Stable coins you like and use?
I don't like and I don't use stable coins. At least not directly.
While normal cryptocurrencies are about not trusting anyone, with stable coins you have to trust the issuer, which, especially in case of Tether is problematic: no proper audits, a lot of bad news over time, quite a lot of fluctuations in the price.
Yes, stable coins have their use, from arbitrage to various services. That's why I said I didn't use stable coins directly: I may have been using services that use stable coins.
From what I see stable coins may be used by some companies for interfacing crypto payments with fiat world.
Unfortunately they can be also used for bad things, especially if they are not backed by the amount of "hard money" they should. And, sorry, but until this issue is 100% fixed, stable coins are generally more bad than good for the ecosystem.
Decentralized stablecoins will fix most of the stablecoin problems you mentioned.
I honestly do not like centralized stablecoin too. My biggest fear about them is that they can be used to attack market. With their poor transparency, manipulators could print lots of stablecoin to manipulate the crypto market.