Why didn't he take more playing time from Kupp? Are you really asking that as a legit question?
Why sign Adams? Again, why ask that?
Sure, the Rams view him as a #3 receiver, mainly because that's what he is. A deep threat and guy who knows every WR position in the playbook. Kupp has missed 17 games over the last 3 years and in those 17 games, Tutu has 61 receptions for 805 yards, 2 TDs. Not #1 WR material but a damn good sub and 3rd option when the corp is healthy. In 2023 when Kupp missed the first 4 weeks, Tutu had 22 rec for 270 yards (12.3), 1 TD. He got 35 targets in those 4 games. Once Kupp came back, he was targeted 32 times over the next 13 games. That's McVay and his blinders but despite that, he caught 17 of those for 213 yards and 2 TDs. The kid has proven himself to be a reliable receiver with very good hands and speed to burn. It's not his fault McVay (and Stafford to a degree) ignore him when the Rams are at full strength. We'll see what he can do IF McVay (& Stafford) gives him a bigger role and doesn't ignore him for large parts of games.