If it’s really going to go down this route then really someone should write one (an extensible PKM app) in a quicker language like Rust, Go or Swift. It’s an Electron app, if people are going to add massive amounts of plugins it’s going to become a resource hog before too long.
Even a completely empty Obsidian vault with no plugins is slow to load on iOS (although I am still running on an 8 plus so it might be quicker on more modern hardware). I actually capture any new notes when I’m out and about in 1Writer because it loads instantaneously then move them into Obsidian when I’m on my Mac at a later date. I only use the obsidian mobile app now if I want to specifically look up or modify an existing note.
I’m not a massive fan of all these extensions for Obsidian tbh, it seems to go against the grain of what the whole thing was originally meant to be about which was basically a note taking tool that had back links and block inclusion like Roam but one that was also portable due to it being markdown. Now people are just writing reams of config in code blocks inside markdown files which are going to be completely useless outside Obsidian unless someone is going to port that plugin to whatever application you want to migrate to. Plugins that add functionality that work within the existing markdown format are ok such as the Calendar plugins, advanced tables, natural dates etc but the config based plugins are no bueno as far as I’m concerned. If they become syntaxes like fountain or mermaid with a life outside of Obsidian I’d consider using them but until that day I will most likely steer clear.
An OS requires a DB, but a DB is not an OS.