These stats are rubbish because it makes no sense to compare placements with previous yr as market is at its low currently, if you have to compare better compare with placements of other colleges.
As far as IITs are concerned the amount of freedom in choosing curriculum in later years, plus foreign exchange programs, research opportunities you get at IITs is unmatched.
Plus at the time of placements the roles offered there are so wide ranging like data scientist, quant, management consulting, pm roles to name a few. Also many companies don't even consider college grads for such roles in other colleges apart from top 8 IITs.
Lastly their campus, it's one of the best undoubtedly. You don't call them overrated/underrated, they are IITs and will always be the best institutes of our country.