Regarding reusable rockets, according to an EASA study I lost since, the answer to that, actually asked, question was: Yes, we could build it, but the there are not enough launches to make it financially viable.

The issue for the really tough things, as in "things that cannot be solved by VC-backed marketing", is to ask random smart people. There is a lot of domain knowledge and industry experience behind them. Still no guarantee tfor success, so. It also has the potential to block these experts from trying something "risky".