Do these other people actually think less of you as a person because of where you work? I get the disconnect between compensation and skill. I think it happens all the time regardless of the companies involved and that your pay is not a function of your actual skill or value but a function of leverage. There is a lot of virtue signaling in leetcode style interviews but the research shows that these types of interviews do not predict job success or even happiness. There is tons of academic research on this. You even see it in the NBA, the NFL, and the MLB.
However these signals are highly leveraged because they map to a compensation measure. Also people with the best offers tend to have the most leverage, meaning they've got multiple offers from equivalents. In fact this was a big problem earlier that the FAANG companies minus Netflix all conspired to suppress wages. Netflix did not because they were small at the time and were definitely not considered elite. Netflix then used mega pay packages to recruit and the rest is history...
So if the probability of getting a job at Google and Facebook is each 0.2%. Then the probability of having multiple offers is 0.0004% .. You mentioned you had a hedge fund offer. That is also pretty good in my opinion. I think all you are missing is leverage and this has nothing to do with IQ. I think your IQ is probably good enough. I also think that IQ is a floor to entry and not a measure of specific success.
So I don't think less of you. You say in another post that you already work at a FAANG! That is quite the achievement.