As globalization increases, there is ever more increasing demand for SF/Bay real estate, it's becoming ever more elite due to the fixed nature of housing.
'All things being equal' in terms of cost, SF would be the choice 8 times out of 10 for people as a destination. SF boundaries are fixed, housing is limited, Houston is large and has room for new housing; Houston's growth is due to affordability, not because it's aspirational.
'Tourism' isn't a perfect estimation of livable aspiration, I mean, Orlando gets massive numbers of visitors each year, but SF gets a huge number of visitors as well without 'Disneyland/Epcot' to draw them in, even with a relatively small population, it's a top tourist destination in the US. [1]. Houston doesn't get a lot of tourists.
Also, Houston's population growth has slowed dramatically, with new births accounting for more than the ingress population this year.
SF/Bay/North Cal is a very aspirational place, Houston is not.