Bob Wachter, who is the chair of medicine at UCSF periodically publishes the UCSF asymptomatic test positive rate. Everyone who is admitted to UCSF takes a Covid test. This rate is the fraction of people who are admitted without Covid symptoms, that test positive. IMO this is a very good number because it's a somewhat randomized population that is being tested in a controlled way, without too much bias.

The latest number he posted, from July 3, was 6.5% [1]. This means roughly 1 in 15 people you come across in San Francisco is positive for Covid. If you're on a crowded bus or train car, there will be multiple Covid positive people on it, and likely one that is contagious. If you regularly take transit and aren't wearing a really excellent mask, it's pretty likely you'll catch it over the course of a month or two.

Back to anecdotes, about 70% of the people I know that fit this description and ride transit in a big city without a mask have gotten symptomatic Covid in the past 3 months. All of them boosted btw.

[1] https://twitter.com/Bob_Wachter/status/1543780608744165376