Struggling to come up with anything new to say about ETFs, but the first response to your OP covers the main meat. Institutions aren't sitting around waiting to get into Bitcoin, they already did. OTC has always been enough to sate institutional appetites, and even without ETFs, there are numerous ways to bet on Bitcoin without owning any (that satisfies what institutionals want anyway).

They wanted to bet on price, not own any. ETFs may have been the easiest route but the emergence of CME CBoE etc proved that the demand wasn't as the door-pounding ravenous hunger that we were told to expect.

Why should this be any different?