While that makes some sense, how do you reconcile this with picking up Malik Willis then? Willis is 26 and Waddle is 27. If Waddle's best years are behind him and won't help Miami much in 2 years than I'm not sure what that says about Willis. You could argue that QB's have more longevity in the NFL than WR's and that Willis hasn't seen much action up to this point so it shouldn't be an issue for Willis, but one of Willis' best attributes is his mobility so it's not out of the realm of possibility he loses some of that mobility in 2 years time especially if he takes some hits over the next 2 years.
There's a lot of rationalization going on with the Dolphins fans these days and not all of it seems to be following the same thought process. In my humble opinion people are putting on rose colored glasses when it comes to Malik. If it's smart to replace Waddle with a rookie WR who'll be in his prime in 2 years, doesn't it make sense to do the same thing for Tua?
That's just my opinion, I could be wrong.
I would answer with the answer you provided. Not only is Willis a year older, but (this is just Google AI's answer) that a QB's prime is 26-34.
It says that WR window is shorter and starts and ends younger.
I am not saying that I think that Willis is the guy but the age window makes more sense than Waddle's.