Why are there so many coins that have higher transfer rates than bitcoin or eth, and the fee is also cheaper than it is for increasing transfers, but I feel like more advanced coins are getting worse. .
Higher transfer rates? What you mean? More transactions than Bitcoin? I doubt that, even if, they are bots putting random transaction to appear as busy coin.
Higher transaction possible at any given moment? Maybe, but at what cost. Keep in mind many solutions work to a certain point, at heavy load everything changes, not scale, bottlenecks etc.
You should understand that on Bitcoin working best in the world developers and on other altcoins often one or two developers of medicore skills.