I think your last paragraph is something a lot of people haven't really realized. We have a good foundation to build upon, if you take a look at our teenagers and some of the early-to-mid-20s players: Mainoo, Garnacho, Kambwala, Hojlund, Amad, Malacia, Dalot, Mount, Martínez, and then I'd add Rashford, Shaw and Onana as more senior players but with still several years left in them. A few players could make a comeback under a new coach too, IMO, like Maguire for example. And then I haven't even mentioned the biggest prospects in the academy like Amass or Lacey, for example, but that isn't down to ETH.
If we ditch the Glazers' "maximum of 3 significant arrivals per season" limitation of the transfer policy, and sign at least 4, but ideally 5 or 6 players this summer, who can contribute from day 1, I think we have a really exciting young core to build on.
Edit: Whether that's with or without ETH, I'm not sure. Just hope we make the right appointment if we part ways with the current manager.