Pakistan gave a scare to Aussies last year with zero great bowlers.
India has Bumrah who is a certified ATG, then they have Siraj who is a good support bowler and did well in Aus last time, Harshit Rana is a very good prospect.
There is no way to tell whether Siraj and Rana will/won't become world class test bowlers in the future, so comparing a young bowling attack to experienced once doesn't make sense here and won't give us the real answer.
Shami was injured but he is back in domestics, BCCI will probably send him to Aus after the first two tests.
We have some good talented bowlers in the squad, Akashdeep and Prasidh are tall hit the deck bowlers who are tailor made for Aussie conditions. All in all, I dont think that we lack firepower with the ball, our reserve pacers are not just young 22 year olds, they have played many first class and A games.