While true, and looking at Jarvis as an internal replacement for TT is very valid, the problem is we'd probably be selling TT while his value is at his lowest in his career so far. That's assuming the front office is even willing to trade TT; I doubt they will.
He's also going to turn 29 this September, and wouldn't fit with a rebuilding team's core (like say Vancouver or Arizona, etc.) unless they want a veteran guy with Stanley Cup experience.
Maybe you could trade him to a contending team for a 1st round pick if we're fortunate, and we then bundle that extra draft pick to push a trade over the finish line for an all star tier top 6 forward with our own 1st round pick ++ like say for EP or Keller (again, both long shots at this point, but I'm keeping EP as my pipedream scenario), or more likely, for a less skilled but still very good forward like PLD or Lindholm. Lindholm is less certain with extending with us due to his likely high asking price and the FO thinking he won't be worth it (particularly in his late 20s).
Maybe we sign a winger like Zucker in free agency this summer to a short contract (that's also a little cheaper than his current one), and that helps as a solid short term replacement for trading TT, or less likely, Jarvis, while still making a trade for a highly skilled top 6 forward to upgrade our offense.