Good players don't need 5 years to mature. When you're talking about Suzuki and Brook types, the road to the NHL is shorter than your average mid to late round selection.
Second, a lot can happen between now and 3 years from now. I don't think you can project who will be here and who won't, with absolute certainty. Neither can you say with any degree of confidence that there won't be any new assets incoming that will make up for the shortfalls in performance by those aging assets you mention. That to me is the most recurring fallacy of these projections people make -- look at roster turnover, year over year. There will be new blood. It'll be up to the GM to make savvy moves going forward.
Not disagreeing about trading for assets with term. However, those types of trades typically happen in the summer. The TDL is mostly contending teams looking for rentals and offering draft picks that won't be in the upper echelon.
Ultimately, you have to either have faith in their ability to replicate last summer or not. I think that's what it really comes down to. Are they going to be able to do it again? I'd like to find out since they were just able to pull that off and I'd like to believe that they have the know-how to do it again. It's definitely worth waiting for, IMHO. Which is why I think all of it can be reassessed after this summer -- see what shakes out. Who they can trade for, draft, sign. We're not that far off.
Like i said for Suzuki and Brooks type of player....they'll probably enter the league next year but before they fulfilled their potential, it will take more years. Look at Drouin and Domi for example, after 3-4 years in the league, they have still not reach their full potential. It took many years also for guys like Scheifele or MacKinnon for example. Eichel is not there yet either after 3 years. Guys like Suzuki or Brooks probably won't get there any faster than them.
Having said that....here's an example of what i'm saying. (Spit balling here and not trying to be perfect but trying to put the team over the top) but i'm going to fill some holes.
Domi - Duchene - Gallagher
Drouin - Kotkaniemi - Kreider
Byron - Danault - Armia
Deslauriers - Poehling - Shaw
Lindholm - Weber
Mete - Petry
Reilly - Brooks
Is this enough to be known as a top team that has a chance to be a contender? Maybe not a perfect team, but honestly, i think that's a very dangerous team for the next 2-3 years with Price in net. At least this is a ton more dangerous than what we have now. Still missing some stars power but we will miss some star power unless we finished bottom of the league which is not in our future with Price in net.
How did i get Kreider?
I traded a 2nd + 5th + Hudon + Evans + Olofsson for him at this year TDL. Overpayment, yeah but i got a goal scoring RW with size.
How did i get Duchene?
This is where i dream a little, but i went nuts in the UFA and offered him 10M. Overpayment it is.
How did i get Lindholm?
Well, i traded 2019 1st round + 2020 1st round pick + 2019 3rd round + Ikonen + Juulsen + Lehkonen for him. Overpayment it is also.
And that's pretty much only an example and i didn't think much about cap space or any of that. And i made sure all my offers were terrible in terms of value but those offers were also too good to pass for the other teams/players.
I still got Romanov and Suzuki to add to this line-up.
I still got Shaw and Poehling riding the 4ht line even if they could play a bigger role in this line-up.
Change the names of the players if you like (I've gone with names apparently available). Now, do we whine because this team don't have a 1st round pick for 2 years and got rid of some spare parts that might have of future or do we sit back watch a team very close of being contender if not a contender. Cause i think this would be a contender for the next 3-4 years.