I hate the state of affairs. That said my guess is what we „gained“ is tons of telemetry, tracking and the likes, engineers not needing to think about performance to get a feature out, which absolutely lowers the bar to entry, high level abstractions and ux and visual bells and whistles of varying importance and quality (infinite scrolling, streaming updates, image blend modes, blur effects, scroll timeline animations etc). People creating Pokémon had to think about every bit in their texture atlas and carefully manage the hardware memory manually. Web devs now try not to forget to clean up event listeners in a useEffect that triggers on mouse move to generate data for an interaction heatmap for the marketing department while 25mb of 3rd party scripts make sure every data broker and their mother is well informed about your digital whereabouts.
Then go ahead and write vanilla JS and raw HTML! No one is asking you to use any of these bad "state of affairs". If you do build a 100+ page SaaS app without any framework, let me know, I'd love to see how it works.