If 'native' plugins are indeed not the way to go, does that mean we are limited to using only functionality supported by browser extensions?
Yes, but the question is how much are you actually being limited by today's browser engines? With things like Encrypted Media Extensions, WebGL, WebAssembly, and Service Workers, there's a whole lot possible today using standardized browser APIs that used to require plugins. Unity's plugin was deprecated because WebGL/WebAssembly gives Unity's engine a compile target that's native to all browsers[1]. This means they don't need to develop and maintain a native plugin and ensure it works in all browsers. It's up to the browser engines to ensure they are compliant with the standard APIs, and Unity writes an engine that utilizes those APIs.
Yes, but the question is how much are you actually being limited by today's browser engines? With things like Encrypted Media Extensions, WebGL, WebAssembly, and Service Workers, there's a whole lot possible today using standardized browser APIs that used to require plugins. Unity's plugin was deprecated because WebGL/WebAssembly gives Unity's engine a compile target that's native to all browsers[1]. This means they don't need to develop and maintain a native plugin and ensure it works in all browsers. It's up to the browser engines to ensure they are compliant with the standard APIs, and Unity writes an engine that utilizes those APIs.
[1] - hacks.mozilla.org/2017/07/webassembly-for-native-games-on-the-web/