What better "form" than an example of something tangible, palpable... where is the "boom" or rather the Bump!, the price is still there and maintains, in fact it did comeback to have +38k, scary ETFs.
The main disadvantage is that they manage a relevant percentage of bitcoin, but the worst thing is not that, it is their influence on traditional media, this can be harmful at some point...
In terms of ETFs jargon, as long as the outflows do not harm the inflows, everyone is happy.