Decentralised is always slower and more expensive then Centralised. Ethereum could change some things more centralised and solve it. Tari is doing it. Etehreum decided to take very wast spectre and have problems with that. They should specialise what they want. Many services that now use Etehreum blockchain dont need such level of decentralisation as Etehreum offers them. You should definitely look at what Tari is doing.