It's because PS Now is real and can't hide its limitations, while Google and MS look great on paper and promises to solve everything.
Server location has influence on your latency, however your isp stability is still more important. Better compression also asks more from the client and will add more lag. Higher quality visuals require more data which will add more lag and be more vulnerable to instabilities. Offering newer games at higher resolutions requires more and faster hardware, meaning less resources to serve more people at the same time. In the end it needs to be an affordable business. Lower quality, older games, or higher priced subscriptions.
Google and MS can promise a lot but will run into the same limits as any other service.







