My 83 Suzuki 1100 needed the synch to be checked on the four carbs every 2500 miles as I recall, which was easy enough with a 'mercury stick'. The 24 valves were checked every 5000 miles. The now antique bike was good for 120mph in the 1/4 mile at around 11 flat, and would do 0 to 60 in less than 3 seconds. I put over 80k miles on the bike before it was stolen. The new bikes are obviously quicker, where $10 grand or a bit more gets you 135mph to 140 mph in the 1/4 mile at around 10 flat, with top speeds often around 180 mph. Expert racers with better tires have hit the high 9s in the 1/4 mile with stock bikes.
My Suzuki was driven hard and never had a problem, only needing tires, chains, a few cables, brake pads, filters, lubricants, etc., and maintenance.