Cheaper contract, shorter contract and currently a better dman than Nurse. I'd hazard a guess that Pietrangelo will probably remain a more effective dman than Nurse for the next 3/4 years. Leaving VGK holding an overpay on the last 2-3 years of Petro, which will be after the cap forces them to completely rip apart their team.
Let it go dude.
Extending Nurse at that cost means the Oilers have lost their ability to add to their team. Next year they have 15/23 players signed and 9m to fill out those 8 spots. Doable, but they aren't signing anyone for much more than league minimum and had better hope their ELCs don't hit their performance bonuses. The only significant cap coming off the books after 2021-22 is Koskinen's 4.5m, they will still have 4.16m in dead cap from the Lucic retention, Sekera and Neal buyouts in 2022-23 (and Neal's 1.9m buyout until the summer of 2025).
And I'll say it now. That Edmonton roster isn't good enough as is - it needs a few adds or some tweaks... And Holland just painted them into a corner - I think next summer will be spectacular watching the Oilers try to fix that team without cap space. Because the additions they made MIGHT get them out of the first round, if they get lucky.
One benefit to that deal is that Nurse will have just turned 35 when it expires - in theory, the Oilers shouldn't suffer too many subprime years...