Housing prices were jacked up because more people moved in than there were houses to live in. The rich tech yuppies are gonna move where they want regardless, so either build enough housing to accommodate them or they will take over the existing housing. If you build, they won't have to kick anyone out

Grandpa gets forced out by increased rent, yes.

Increased housing supply almost universally decreased housing prices.

If you don't want renter Grandpa to be forced out, build more

Any definition for anything is tautologically true if you ignore exceptions