Regardless of whether the conclusion is "yes you have x" or "no you don't have x" the diagnosis will be accompanied by a detailed analysis of your psychological condition. Whether or not you are diagnosed, that analysis will cover the issues that led you to believe you may have that condition.
And it’s very expensive to get the diagnosis, it can be up to $20k in California
Nobody will accommodates you.
Suing for ADA violations will cost $20k just for a retainer. And then it's a gamble if you win or not.
And the US government wants to aggregate us into a list for who knows what reason.
Mental health, like physical health, requires action on your part. If the only thing you're seeking from a diagnosis is accommodations from others, then yeah, you're probably going to be disappointed.
There is a post here about someone who was misdiagnosed and bipolar and that later came up when security clearance was needed for a job.