That's a broad and unfair generalization and implication. People decide to move for all sorts of reasons, and then perhaps a job determines a destination. People who move to a cheaper location (which can be young people starting a family or retirees or any life stage in between) are also putting cost or quality of life "ahead of friends, community, and likely family."
If you are a person who makes friends you will make friends in your new community. Ubiquitous networking lets you keep in touch to the level you wish with friends and family. When I go back to my home country I see friends with whom we just pick up mid-conversation as if I'd just been over their home the day before.
Life has been so for thousands of years. Not necessarily a sacrifice as you frame it.
I'm pretty sure that most people moving to SV/SF or most high cost areas really do so because they (or their partner) got a good job offer there, and especially in the case of tech and northern California, because there's a high density of other job possibilities as well.
People do just decide they want to move someplace but I doubt a lot choose the Bay area unless there's a job offer attached.
Shouldn’t they be happy that they can have their cake and eat it now?
Move back closer to those friends and family and keep working your dream job!
I personally prefer WFH but think WFH is secure and don't want to unnecessarily hurt RTO but I'm not sure I'm right.
I feel lucky to have been born and raised in SV. I can have my cake and eat it too - remote work, in person work, whatever - and I can still go out and have lunch with friends I've had for 30+ years.