Gas burners are surely made better. As a fleet manager for 14 plus years I regularly saw GM trucks get 400,000 miles with no internal engine repairs. One truck we took to 652,000 miles the motor was still running fine but the transmission blew. These were 4.3 V6 mostly but the 4.8 and 5.3's appear to be doing the same (some would burn some oil). These trucks carried minimal loads at highway speeds for their entire life and would run about 100K miles per year. Of course I was doing my job keeping up with the oil changes and other required maintenance!
I also had a 1982 Ski Nautique 2001 I owned for 17 years and put about 5,000 hours on it. At about 4,000 hours we had to do a light overhaul. The cylinders did not have to be bored (only a few thousandths wear!) and it ran as good as day one after that. I just reach a point I was getting older and wanted a better wake and was tired of working on that OLD BOAT!