They're trying desperately to win a Superbowl before this core goes into the tank, in order to endear themselves to the fickle LA market.
Yeah, I heard the exact same thing in 2018. They went 13-3, 9-7, 10-6, and now are 7-1. The three last years, that 32-16 record was with Jared Goff, who is roughly an average quarterback, maybe a bit worse.
1. Success is built through the draft;
2. Teams overvalue draft picks when it comes to trading for established, valuable players. The Rams identified this and capitalized on it.
Both of these things can be true.
They'll eventually stop being one of the league's better teams, though looking at their roster, it isn't crazy to think they still have a few more years left, or in other words, a window of opportunity that lasts over 5 years. At the end of it, people will say "told ya so!" about not having first round picks or young guys to build around, but the fact is many teams in the NFL won't be much better off, though they won't be coming off of a long-term championship window.