It's not playoffs or bust. With a #1 C, D and Goalie, making the playoffs should be the minimum year in and year out. Thanks to Benning there are major roster parts that need to be at the very least rejigged.
Fact of the matter is that players move on. Does it have to be JT? No If the offer isn't good enough and his contract demands aren't insane then yes because of all the points you mentioned, by all means keep him here.
But how many of Petey,Hughes,Boeser,Demko,Miller and Horvat do you think will retire Canucks. It won't be all of them.
It wasn't with the Sedins,Kesler,Burrows,Edler,Luongo.