To add to the sibling comment, there are also many different ways of making a living doing this stuff:

* You can find killer clientside bugs where the bounty will cover a year's worth of compensation (bear in mind you'll get maybe 1.5 of these payouts a year on your own if you're good but replacement-level)

* You can find these kinds of bugs and work with brokers to sell them to grey-market buyers along with enablement/implants --- more development work, a little more market risk.

* You can find smaller, easier bugs (serverside, web bugs) that get nothing resembling these kinds of payouts but are much easier to find, and make good money on volume. This is a much more common way of making a living on bounty payments.

Yes. There are plenty of folks who submit to the company I work for who live in regions of the world that are extremely low cost of living/salary (in USD terms) and most BB programs pay out fixed USD rates. It can be very lucrative.