I’m not sure why Stanford isn’t ranking higher on this thread.
There are nearly 10,000 grad students at Stanford alone. So, I don’t think there would be that much of an issue with " older" students.
Palo Alto is not exactly the sticks. Nearby, there are lovely towns like Mountain View etc.
As @ucbalumnus mentioned, San Jose is not far off, has great concerts, sports teams etc. And SF is not exactly that far away. Both are accessible by train
You can’t beat the weather in the Bay Area. Four seasons might be fine for some, but it depends on what YOU like. I prefer this kind of weather personally. You are near beaches and near to skiing (Tahoe etc).
I tend to view the Bay Area as a giant circle (ok, compressed oval is more accurate) around the San Francisco Bay and includes great and very diverse places (in a clockwise direction) like SF, Marin County (which is stunningly beautiful), Berkeley, Oakland, San Jose, and Silicon Valley, and then back to SF again. If you have a car, it’s somewhat easy to get around (much easier in 2022 than in 2019 before the pandemic) as the traffic situation has improved a bit since 2020.
You also have three major airports so it’s easy to get to anywhere in the US or most places around the world.
You also have another world-class institution nearby (UCB) that enhances everything just noted above.
It is also very expensive here, so there’s that to consider.
You are extremely fortunate to have this wealth of choices. You clearly have done exceedingly well! But these are all very different schools. Go where YOU will be happiest based on research, good advice, and your gut feel. The localities for these schools are quite different.
ETA: Take a look at this thread. I’ve found it really helpful on things to consider when picking schools: What qualities/aspects do YOU think are worth paying for at college?
Use all those skills that got you this far to research the heck out of this decision! I guess you may not have time to visit these schools before May 1 if you haven’t already done so. But I hope you have visited these schools some time?
There are all fantastic institutions that others know better than I do. However, all I’m saying is to consider all of them, including Stanford.