The alternative is no pay, not higher pay. If the employer thinks that you don't meet all the qualifications that they'd like, there are two reasonable outcomes:

1. The most likely => you don't get any offer.

2. You mutually agree to take a lower offer. It's a lower offer, but it's also much, much greater than zero. You got your foot in the door, can develop your skills, earn an income, and make progress in your career instead of continuing to interview.

If you don't meet all the qualifications how are you getting your foot in the door? How are you getting interviews without qualifications?

I think the most likely scenario if you don't meet the qualifications is you get ghosted.

With salary requirements, maybe people will waste less time on pointless applications, and there will be less ghosting.