You're complaining about MPA. Maybe if you choose SPA with vanilla React you would've felt that for the last 8 years there's been a flurry of conversation and innovation that's specifically not about SPA. The conversation around SPA has been frozen for nearly a decade.

Unless maybe you want to start talking about CRDTs? But that's kind of niche, and CRDTs are actually an old conversation, one which started before React was first released. That should give you a sense at the pace of conversation for SPAs.