FWIW, it seems like nowhere is this truer than SF/SV.
Outside the bubble, it isn't always the case, or the structure can be a bit different, but salespeople in the Valley (as it were) are a different breed.
I work with tech salespeople with a variety of former employers as tech sales people, and I've never heard of anyone having worked without a commission. I'm vaguely in tech sales myself (solutions architect) and I'm on commission too, and so is everyone who joins our division from similar employment (solutions engineers/architect, or even customer success folks).
Ask a local real estate agent or real estate broker how much base pay they make. Or, heck, a car salesperson or an ad salesperson at your local TV or radio station. It’s all commission-based. In some of these fields in the US the norm is 100% commission-based with no base pay. In others someone might make one to three times minimum wage, but will end up being some of the highest-paid people in the company based on commissions of anywhere from 1% to 50%, depending on the industry.
Outside the bubble, it isn't always the case, or the structure can be a bit different, but salespeople in the Valley (as it were) are a different breed.