Its an interesting stat but Hobbs faced other challengers and his ave is still high 50s. Neither does it bear repeating that Sunny managed to dodge (by circumstance not design) the best WI and even Aussie teams. So I don't think a distinction can be made btwn the 2 on this issue. On another matter; apart from the unique example of the WI I wouldn't always agree that post ww2 attacks are consistently better than before that war.
It's true that Gavaskar never faced both Lillee and Thomo together because of WSC, although he did face them separately from time to time. However, I think that Gavaskar faced his fair share of West indian quicks at their peak. For example;
West Indies V India (1976)
Bowlers = Holding, Roberts, Julien, Daniel
Tests = 4
Runs = 390 at 55.72
Note: This is the infamous series where Bedi quit the Sabina Park Test during second innings due to intimidatory bowling by Holding inparticular.
West Indies V India (1983)
Bowlers = Holding, Roberts, Garner, Marshall
Tests = 5
Runs = 230 at 30.00
India V West Indies (1983-84)
Bowlers = Marshall, Holding, Roberts, Daniel, Davis
Tests = 6
Runs = 505 at 50.50
The Pakistan pairing of Imran and Sarfraz in the early 80s was useful, especially at home;
Pakistan V India (1982-83)
Bowlers = Imran, Sarfraz, Qadir, Qasim
Tests = 6
Runs = 434 at 48.22
Gavaskar of course scored plenty of runs against Willis and Botham both in India and England, but seemed to always have problems against an England attack led by John Snow. I assume that's because Gavaskar was still finding his way in the early 70s.
Overall, you would have to say that Gavaskar saw a good number of great fast bowlers at their best. However, upon reflection I don't think that we should get too carried away either as he wasn't exactly swamped with ATG attacks as we might assume.