From: Albuquerque, NM
It took some trial and error, but SpaceX finally nailed the return of the Falcon boosters. In fact, half the fun of watching their launches now is watching the booster return home. Now, if they can figure out how to recover the Merlin Vac engine they'll have nailed the re-usability factor of for Falcon launches.
That probably won't happen. By far the majority of the cost of the stack is the first stage and recovering the second stage doesn't look economically viable. They re-enter a very long way downrange at near orbital velocity. The heat shielding and strengthening required add too much mass. They're recovering the fairings, which are expensive, and that's about the best they can do for the second stage.
Yes, that is/was the problem facing the team. Though as late as 2018 Musk was still actively talking about trying to find a way of recovering the second stage. It may have been him simply musing out loud over something more aspirational than practical.
It would've been cool to have seen if they could figure out a way to make it work. Even more interesting would've been the how, would a parashield work or Elon's 'Giant Party balloon'. We'll never know as the team was re-prioritized that year to focus on Starship,
You and the rest, you forgot the first rule of the fanatic: When you become obsessed with the enemy, you become the enemy.
Jeffrey Sinclair, "Infection", Babylon 5