In short, technology has changed a lot of things, but we're still human animals
And because of that, people who were already living there should have to move away?
If they bought in, they don't have to. If they had got their act together 20... 40 years ago and got rid of some of the NIMBY stuff causing so many problems there, that would have helped too. If there were enough housing, no one would "have to" move away.
But no, in most western countries, there is no right to live in a city just because you currently happen to live there. If you want to live in an inclusive place with room for everyone, you have to ensure that the right policies are in place. If it's something you care about, you should get involved with these people: https://twitter.com/sfyimby
This pops up in every thread about housing.
The answer is that there's still a ton of value in being in the same place as other people. Stuff happens faster. Ideas are more easily shared. Spontaneous ideas are born.
Of course at a certain point, having to pay someone way more makes it just not worth it, but that seems to be a pretty high number for a lot of companies.