"I never understood why investors need to be 'close.' "
Many of them want to "influence' the companies they invest in, to give them the best chance of seeing a return. They feel they can't do that as effectively if they can't hop in a car and drive to the office quickly.
"I also don't understand why most startups need an office."
Many managers, startup or not, are afraid of remote work, and feel that not being able to see butts in seats means that people are slacking off.
"As far as 'access to talent,' that's a bullshit metric as well. Remote workers can be anywhere. "
But as we've established, most of these companies are not set up for remote work. As such, remote workers being anywhere isn't relevant.
"As far as investors, who cares? If you have a product people want to buy, investors will come to you."
Ahh yes, the old "meritocracy" myth. As it turns out, simply having a good product isn't enough to succeed.
"It's a myth that proximity matters."
Except reality has not followed your logic.
"There were investors long before Silicon Valley startups were a thing. Plenty of billion dollar companies founded everywhere else."
Yes there were. But it's significantly harder to do it elsewhere given the realities of the situation.
Feel free to start your company wherever you want and show us that we're wrong. I'd be happy to have the pool of startup locations be more diverse.