What would Siri’s market share be if you could easily install Google assistant on iPhone? How much more investment would Apple have put into Siri if they had to

What would Siri’s market share be if you could easily install Google assistant on iPhone? How much more investment would Apple have put into Siri if they had to compete? I haven’t noticed any improvement in Siri in close to a decade of being in the Apple ecosystem. The most frustrating thing is that every time I ask it to “turn the lights on”, it thinks I’m saying “off”. I grew up in the US and have no notable accent or mumble. Note that there are hacky ways to add google assistant, but it doesn’t get integrated into the OS in the same way