Tyler is still good, but there is only so many yards an aging #3 WR is going to get on a team with a very limited time-to-pressure rate. Very rarely is he going to be the primary read on a route, he's very rarely going to be the release valve on most routes, he's the "I'll get to you if I have time and the first two guys are covered" route. (Spoiler Alert: We basically never have time.)
And, yeah, as amazing as Tyler has been for us (ROH inductee for sure), he definitely has the contract of a #1 or #2 receiver for next year... and those days are done. Could he restructure, take a contract more in line with his reduced role and production? Sure, but if I were a betting man, I'd put it on Lockett retiring this offseason.
Going to miss seeing #16 out there when the time finally comes, though.