I think the other issue is that while Austin is awesome, Texas is....not. With all of the controlling social politics that conservatives are pushing, most tech-based people want to get out while they can. They have money, it's easy for them to up and move, and they can get a job anywhere. Why the hell would they want to stay in Texas?
Maybe, there are lots of awesome places and people like different things. But I've travelled a ton and stayed long term in a whole lot of places and Texas is in many ways one of the better places to be in the US, which appears to be generally borne out by the continuing net inflows to the population.
But many startups are now choosing to leave the capital city they once flocked to because of the rising cost of living, low funding, and lack of diversity, according to TechCrunch.
Because these things are better in California? Where are they going?
Things are bad for tech (and business in general) but it's not better anywhere else.
There's certainly more diversity in parts of California, and "low funding" may refer to incentives and tax breaks given to companies to do business in an area.
Remote work, despite what many of the Business Journals have been doomsaying, is still very much a viable option. So they don't have to stay in Texas, and they can operate from wherever.