I mean, kind of leaving aside the obvious social aspects of meeting people and helping to maintain friendships over decades, I think the biggest impact for me is that DMing made me a lot more confident generally, able to deal with attention from multiple and difficult conversations better (IRL anyway, maybe not online!), much more aware in social situations when someone is getting left out, or when a voice isn't being heard or the like. This really helped me in the last decade or two both at work and as a juror. At work, it means in meetings I can be very helpful in ensuring people get heard, and opinions get discussed and so on, and as a juror, it gave me the confidence to accept to act as the foreman on those cases, and to then use that to ensure every juror got their say, got to ask questions about things they didn't understand, and we didn't just have a situation where a few loudmouths or bullies dominated, or where people were afraid to ask questions.
As well as that, the heavy focus on rules in RPGs has made much more aware of systems, and particularly how systems can shape behaviour and render certain outcomes more desirable, or more likely, or both, which has been useful both in life and in my work. I can often see things wrong with systems that other people aren't getting, and people often come to me to look stuff over and give some insight into anything that might be missing or undesirable about it.
And as a minor bonus, RPGs also made me better at math, both the instant kind of addition/subtraction, and doing more complex math because of stuff like Traveller TNE's Fire, Fusion and Steel, or Guns Guns Guns. None of it is high level, but it happened at exactly the right time to keep in practice and interested in stuff and helped ensure I passed my maths GCSE with a good grade (A, I think).
It's interesting that some people lost time when they should be doing school/real work to RPGs. I don't think that's really been true for me. Other stuff has done that - video games, particularly MMORPGs, and forums and the like (I don't post on Twitter because I'm afraid I'd never stop), but when I am in a more TT RPG-oriented mode I tend to do better with that kind of thing, not worse.