The next layer of cynicism down is more complicated. I'm going to make this up to protect the guiltocent, but I've been on the receiving end of security assessments that ask the moral equivalent of "Do you salt the MD5 hashes you use to store password hashes?" and we end saying Yes in some large number of words because we use bcrypt/scrypt properly, or some industry SSO, or our systems communicate with an internal CA TLS authority where "passwords" aren't even in sight, or whatever other solution leaves salted MD5 in the dust.
It's literally a deal breaker to send back No, so there's a lot of incentive to do what it takes to send a Yes back.
And "subsequent lawsuit" is a very distant threat in this case.
Less cynically, there are some standards that do have some non-zero teeth in them. Some audits are challenging and at least rate "a good exercise". But that's what I mean by even if the vender truly believes they are compliant with ISO-Thirty-Three-Million-And-Two-Subrevision-A24, they're just one error away from ohnoyourdatabase anyhow.
The net-net of it all is that, as I sort of alluded to, are these assessments worthless? I mean, no, not quite literally zero. If you send one of these documents to a startup of two dudes and a cat and they claim ISO-Thirty-Three-Million-And-Two-Subrevision-A24 compliance, they're lying and the person examining their assessment at least has a chance to be suspicious about it. But in real terms, are they going to be the difference? Unlikely.
Or, let me put this another way. I would bet substantial money Okta has in their possession a response to their questionnaire from Rightway Healthcare in which Rightway Healthcare sings the praises of their immense, extraordinary, back-breaking, industry-leading security efforts, complete with citation of the relevant industry standards they comply with, and that it looks as good as anyone else's answers.
Yet, here we are.