I think the barrier, in my experience, is folks thinking they have to drag their D&D group over to another game. When I branched out it was always a combination of interested existing players and a search for new interested fans of other systems. If you limit yourself to the same folks, its not likely you will ever get to play something outside the collective interest.
the thing is (for me) that as I get older I have less and less time to hang out. In my 20's I could have 5 different groups of friends with 5 different hobbies and still see and interact with all of them.
I am in my (lets call it mid) 40's, go back 15 years and I could have a board game group, a card shop group, 2 different Larps (one in door year around 1 outdoor sprin/summer only), 3 or 4 TTRPG games running (sometimes just a bunch of 1 shots like Pokethulu furry pirates and kobolds eat my baby, sometime deadlands, rifts, D&D) and little over lap between them and 0 overlap that was for all of them... and still date (occasionally) and play some basketball and do the chores my mom insisted I do, and still work.
Today I am in 2 nights of games, if we are going to do cards or board games it is on those nights INSTEAD of gaming... trying to do a 1/month game has proven to be impossible to schedule.
Why is that, because we own houses/condos... we have major Significant others (spouse or fiancé or at least long term living with) some of us have kids, and those that don't have kids adjacent (nieces and nephews) and the 'chores' are less assigned and more "I need to get this done" even the chores for the live alone ones are no longer "Gee I could not do laundry this week and wear these pants" for the most part.
So if I take my buddy Linda as an example... she didn't want to play 5e at all. So I have not seen or talked to her outside of facebook in almost 3 years... she still got a save the date for my wedding next May, and she messaged me her and her husband wouldn't miss it... but if we had still been playing 4e she would talk to us weekly.
another example is a friend that came BACK for 5e. Jim didn't like 4e. To this day he would prefer PF/3e. He though had found as his groups for PF broke up he didn't have a steady game... he came back and missed us all. He wanted to hang out. I saw him SLIGHTLY more during 4e and early 5e then I have Linda now (I mean no coivd helped but also his older brother stayed with our group for 4e/5e)
I don't know maybe it's just me, but I find I CAN'T keep 3 or 4 different groups of friends going in my 40s where I could have kept 10 groups in my 20s