Old bikes are fun to tinker with and ride short distances.
Modern tech is far more reliable, never mind modern materials in engines. It is rare these days to check valves the first few times and really need to do any adjusting. Not so on old bikes.
I'll take a newer bike for reliability any day. Change the oil, do your maintenance, and ride it. Carry less tools. More time riding, less time fixing. I'd much rather plug a tire than change a tube on the side of the road, which imho is another plus for "new tech" i.e. tubless tires.