It definitely doesn't guarantee anything but it helps to accumulate as many higher pick prospects as possible. It isn't just drafting Top 5 but also drafting at the top of the 2nd, 3rd etc. The big thing will also be what type of trades/signings Blake does with these assets.
A big help for TB was being able to move Bishop due to having a better goalie in the wings and picking up a Top 4 young d-man for him. Getting Sergachev for Drouin also salvaged a miss of a 3OA pick. So you are correct that there is more to it but the sucking helps put you in a position to make more impactful player management moves. This is why many of us say Blake is doing the easier part of GM'ing right now but his feet are going to really be held to the fire starting this off-season and into next season.
I'm not sure this offseason is the one. He
still has holdovers to cycle through. He's going to have to deal with old guys with Doughty, Kopitar, and Quick for a while, but Brown and Carter are gone after next year. Petersen is a UFA after next year. Quick will be turning 37 in 22-23, so they have to figure out what Petersen is. He's the goalie equivalent of Iafallo on the roster. Almost the same age and everything. Do you invest in him long term?
This year, we're very likely not going to see many of the young guys we care about. Blake doesn't even have many, and maybe no, UFA's to trade at the deadline to open up a spot for youth for the last few weeks of a season. There are a lot of RFA's this summer, some of which will likely not be brought back. So next year is when we start seeing more of the important youth, and then as of right now, Brown, Carter, and Maatta open up $14m in cap in the summer of 2022. By then, Blake should have a better idea of what he's got, and then you try and take advantage of the ELC's for a year or two, before some sort of cap crunch comes along.
This year, still killing time. Next year, there has to be real growth. Then a push. If it doesn't work, that's when Blake is gone. Spring of 2023 or whatever. Or, he's gone by the end of Kopitar or something like that. It would depend on how disappointing 22-23 is.