I’m in my 50s and have a uni for every occasion, while the occasion more often than not is bike trails with relatively smooth surfaces. Usually black top or crushed limestone. I ride a 26er nimbus muni with a 3 inch duro wildlife tire that I ride on rougher surfaces. I love this uni but it is a little heavy. I also ride a nimbus road 29er with a 2.25 schwable marathon tire.this is my favorite uni to ride and I have it rigged with a t bar and a disc brake. Now I will note that when I started back riding I bought a udc trainer used with cottered cranks. At 200 lbs I managed to rack up 2000 miles on this uni over several years and loose some weight. I still own and love this uni and it is remarkable condition, hub, wheel and cranks all on good shape
I believe there are a lot riders like me out there. We are older and want to ride but maybe not muni or trials. I’m the same way with my bicycle, at my age I treasure my bike trail trips. I’m not looking to do down hill single track, I just like to ride and enjoy my time outside. Best of luck to you and as a side bar I have bought all my unis used.
Take a look at this thread. There are others like it you can search for.