The premise of the argument is that the majority of financial transactions should take place on-chain, which is the same shortsightedness that led to the 2015 blocksize war. Bitcoin isn’t optimized for that, its best use case is a settlement layer, with most private transactions taking place off-chain using Lightning, ecash, etc. “Junk data” is entirely subjective (“Well, you know, that’s just like your opinion, man.”) and like @verbiricha said, will eventually be priced out.