The issue is that the "average depositor" is a Silicon Valley venture capital funded startup, or in other words, an investment vehicle for wealthy venture capitalists. SVB was not a "mom and pop" banker.
Of course some of the startups banking there were not themselves wealthy (yet), though some of them were. But in general, that's the goal of these startups, for both the investors and the founders, to go big or die trying, in contrast to a small business, which may remain relatively small forever. The ultra-wealthy are the primary beneficiaries of this startup system, regardless of whether any particular startup happens to be making a lot of money at the moment.
There's a reason the FDIC only guarantees $250K. That's enough to cover mom and pop. Moreover, depositors who were over $250K were very likely to get a substantial portion back, sooner (with advanced dividends) or later. It was never going to be a total loss, regardless of bailout.
Making every depositor whole comes at a cost. It's a bit of a copout to say that taxpayers are not funding this, because taxpayers are customers of the more responsible banks who have to pay a fee to cover the cost. The costs will get passed along, just via a more indirect route that attempts to cover the political asses of Biden, Yellen, et al.
The lesson here isn't that individual startups should have chosen a bank more wisely. It's unclear how that was possible, or how they could have predicted what would happen. The lesson is that the entire SV VC community is too small and insulated, both geographically and culturally. There are too many eggs in one basket.