My advice would be to stop worrying about scores (IQ, SAT, whatever) — you’re not in high school any more. And stop comparing yourself to other people.
Are you meeting expectations at work? Getting solid reviews from your manager? That’s what matters.
So you don’t test well? So you didn’t get into the big name companies that have famously grueling interview processes and reject the vast, vast majority of candidates? So what?
There are plenty of other companies out there that need your skills. Badly.
Yes, a bunch of them cargo cult the same ridiculous interview processes as the FAANGs. But not all of them do.
Find the ones that don’t. Find the ones that instead send you a small take-home that mirrors the type of work you’ll be doing daily. Show them that even if you may not be good at solving algorithmic puzzles under pressure, you’re good at writing software.
That’s what matters.