Actually, the advent of lead-free gasoline had more effect on engine life (improvement) than any other single change in the last 50 years.
Less valve problems, spark plus last longer, easier on the engine oil, less engine corrosion, and longer muffler and exhaust life, to name a few.
One tuneup every 60,000 miles, which involves replacing spark plugs, PCV valve, and filters vs one every 12000 miles that included replacing plugs, points, condenser, filters and PCV valve as well as adjusting point gap (dwell) timing, carburetor, choke and valve clearance?
Hands down, I'll take today's engines - and I LOVE old cars.
And the old stuff was really HOT if it produced 1HP per cubic inch of displacement. Almost all of todays econoboxes excede that output.
With chain driven camshafts, if the oil is changed often enoug 200,000 on the chain is not a stretch. 60,000 miles on a 318 or 350 was doing pretty good
More expensive when it breaks? Perhaps. But you spend a significantly lower number of hours wages today to maintain the average car than you ever did in history.