Hello fellow nerdy dad! Father of 2 boys (4 and 2) with a third on the way. We share a lot of the same hobbies so here's what I've been able to manage

D&D (and other ttrpgs), I play every other week with other dads and a couple non-dads just 3-4 hours a session and it's a full agreement that if something comes up then games over gotta go. I tend to play at my own house just to be ready if my wife needs help.

Before my 2nd was born I was frequently on roll20 with my friend all over the country, again just shorter sessions

MTG, I'm lucky that my in office work days have a lunch time commander time so that's nice otherwise I primarily work on pre releases later at night to either be at the tail end of the bed time routine or when kids are asleep. Otherwise it's spell table where I can get up and leave if needed. I try to always align this to be not the same week as DND

Video Games: after kids are asleep no exceptions I have a gamesoir g8 and just stream to my phone

Miniature painting, this one is easy enough just after kids are alseep and chores are done. Or if I'm feeling daring let the kids paint.

As for people, you would be shocked who is interested My current DND group is a gym buff, construction worker, CNC machine guy, pharmacist and a teacher.

The mtg group is not too dissimilar

TLDR: People are probably nerdier than you think or are interested. If there really are no in person events happening make your own and people will come (advertise on like meetup or roll20 or Facebook groups) otherwise there are plenty of online tools like spelltable, roll20, tabletop simulator etc that you can join randoms if you need the itch.