I also think the Worlds are slightly overrated.
In the old days (the 20's), the Worlds were known as Wolber GP and raced solely among the winner of a handful of big classics of that time (like the Masters in tennis). The label World Championship was justified.
In this respect, in the UCI ranking era, I had an idea. The ranking should decide who should be selected. For the RR, the Italian squad, for example, should have the first 9 Italian riders at the ranking. Thereby the national coach could let a second "leader" like Ballerini did when Bettini was there. For the ITT, the - let's say - 50 best performers at UCI ranking in ITT's should be selected whatever their nationalities.
This is much more difficult now, since the Pro Tour.
I believe the system by national teams gives it a weaker field than the major classics. I'm not an opponent to it though. It gives the race prestige and uniqueness.
But you just have to take the 1976 edition. The first 8 were champions and then you had Don Allan of Australia (9th) and Mike Neel of the USA (10th). Those two guys never made such performance in major classics simply because the Italians, the Belgians or the Dutch had a limited number of riders at the Worlds and an unlimited number of riders in the classics (and they had the best riders at that time).
I also remember a great controversy in 2005 when Luxembourg had the right to only one rider while they had two riders who had good results that season (Kirchen and F Schleck) while Iran could have 3 of them (among others). McQuaid's insane conception of globalization. (pf course, now the problem is just opposite. Too many Luxos, lol)
Also depending on the year, the course might really be cakewalk. Remember Zolder 2002.
With regards to the hardness of the race, in my opinion:
Paris-Roubaix >>>>>>>>>>>>> Worlds (whatever the route)
With regards to prestige:
Paris-Roubaix = Worlds