I haven't done a deep dive into this or anything but any time you trade futures (especially 1st round picks) it hurts you in the sense that you deplete your prospect pool.
Had we just kept all our picks, it stands to reason that we'd have at least a couple of players we drafted contributing to the team today, that's the theory anyway.
The most damaging pick so far has been the one sent along with Marleau. That turned into Jarvis who is a blossoming star. Our other first rounders that have gone out the door haven't been as bad.
2019 1st for Muzzin turned into Tobias Bjornfort, who is a journeyman at this point and on his third organization.
2020 first turned into Jarvis, see above.
2021 first turned into Corson Ceulemans, who according to The Athletic's prospect report has hit a plateau in his development and doesn't project too well.
2022 first (to dump Mrazek) is Sam Rinzel, an offensive defenseman who is developing well but still years away.
2023 first turned into Otto Stenberg, an undersized centre with a scoring touch.
For the most part with our firsts we've turned out relatively ok, certainly no disasters like missing out on Niedermayer/Lindros in '91 or Luongo in '97. Right now Jarvis is at "Brad Boyes" level missed out on which while not ideal is an acceptable trade off for "win now" deals. Or at least it would be if the trade brought in a piece to help us win instead of being used to dump a stupid contract.
Those last two-three picks still have time but I don't look at them and wish we had held on, only Jarvis really hurts. Granted we may have picked different players but in our range (5 picks higher or lower than our slot) but not too many stick out. In 2021 we'd have needed to trade up to beat Dallas to Wyatt Johnson, and 2023 we got who we wanted thanks to trading Sandin away (Cowan). Speaking of, we should have another 1st round prospect in this system if not outright on the team, but Amirov's passing was a tragedy no one could've foreseen.
In my opinion our most missed futures have been prospects who were already in the system or on the roster that we sent away. Moore, Marchment, and Durzi all would've been in line to join the team and contribute at some point within the last three seasons had we not dealt them. Only now are we seeing a wave of prospect reinforcements on the team in Knies, Robertson, McMann, Holmberg and potentially Grebenkin. Defence is really barren in that department unless you want to count Liljegren still, maybe Benoit but most of his development happened in another organization, not unlike Jake Gardiner.