The technology has caused architects to create many more of what are effectively 1/2 par holes for the the average golfer. How many golfers do you think have a realistic chance of hitting a 430, 440, 450, 460 or 470 yard par 4 in two? Holes of that length are almost always a par 4.5 for the average golfer (if not a par 5). Unfortunately, courses today have more and more par-4 holes well in excess of 400 yards.
I remember when a 420 yard hole was considered longish... no more. The 8% of golfers with a single digit handicap can usually play those holes with a driver-8 iron, while the other 92% of us usually require a driver-4 iron. When par four holes require the average guy to hit two "woods" then it is definitely a 4.5 (or better) hole.
Also, don't forget all of the +200 yard par 3 holes that are omnipresent on today's courses. I played a course recently that had three par 3 holes well over 200 yards each from the "member's" tee. This might be fun for a skilled golfer, but it's just a slog for the average guy.