I think in American sports, especially in baseball and hockey, but sometimes in basketball too, players often sign very long contracts and often continue to improve or keep high performance levels steady.
I suppose players are different, and some would lose motivation to try because they need that carrot of the next big contact dangling in front of them, but others might not be, they might appreciate the security of a long term contract and the commitment shown to them by the club.
As a fan, it's concerning in some ways because we can already see the issues with this strategy when we can see 1-2 years into an 8 year contract that a player isn't up to it (Mudryk), and then you're stuck with the player, and basically have to hope the player will be OK with reduced wages at a different club and accept a transfer.