I think the downvotes are unwarranted, but the point being made is that in a land-scarce environment like SF, a developer would pay out the nose to buy your single-family home, tear it down, and build something with higher density... if the land was zoned for it.
Sure, once this happens enough times, and supply starts to meet demand, you're absolutely right in that a single-family home's value will drop when it's adjacent to an apartment complex.
(Then again, it could also be quite valuable to someone who wants a single-family home when the norm becomes larger complexes.)
Also note that the current value of your home is driven almost entirely by artificial scarcity. There's nothing intrinsic about it that makes it worth so much.
Sure, once this happens enough times, and supply starts to meet demand, you're absolutely right in that a single-family home's value will drop when it's adjacent to an apartment complex.
(Then again, it could also be quite valuable to someone who wants a single-family home when the norm becomes larger complexes.)
Also note that the current value of your home is driven almost entirely by artificial scarcity. There's nothing intrinsic about it that makes it worth so much.