Moved from CO to WA about 6 years ago now so I can kinda speak to this. Biggest difference is the winter weather. If you can't handle rainy/dark you won't like it, a few of the friends I met here have already moved south for the longer days and sun. I'm not as bothered by it but you have to be super on top of your mental and social health, it's way too easy to shut yourself in your house up here. Also be ready to ski in the rain sometimes, it's not ideal but it absolutely sucks if you're not prepared.
2nd difference is the people. You won't see many baggy fits or NS stickers. The cities (and ski areas) have a strong tech worker presence. Think arcteryx, sprinter vans, and lots of barely trained dogs but not as many shredders that love skiing in the same way people in CO (or UT) do. Not to say that you won't meet chill people to ski with, just that it's harder and the culture is a lot more generally outdoorsy than ski focused.
I will say that there are a lot of positives to living in WA. First and foremost you'll earn/save more money. I've found that it's way easier to reduce my cost of living (roommates, costco, transit, etc.) here than it was to wait around for a living wage in CO. You'll also meet more genuine friends, IMO a lot of CO skiers moved there to live a life they saw in some corny tiktok video and had a hard time getting over themselves. Not having to sort through dozens of out of touch wooks to find ski friends has been super refreshing.
TLDR the ski culture in WA is less active and the weather might be shit, but at least you'll have more financial stability and see fewer white people with dreads.