But losing most of those players didn't make Chicago a worse team. They even won another couple cups after a bunch of those guys were gone. Chicago's window has closed because their core got too old. Toews isn't Toews anymore, Keith isn't Keith anymore, Hossa's gone, Crawford's brain is scrambled and Seabrook is done. Chicago is the perfect example of a window NOT closing due to cap constraints.
I'm talking specifically in the time period of when they were competing for a cup and right after (so 2010 to about 2017. They won 3 cups in there). I don't think they are competing for one now, or even the past year or two. Hawks won the cup last in 2015. They were 5th in the league in 2016. 3rd in the league in 2017. It wasn't until 2018 that the wheels fell off.
Most of those guys I listed are now washed up, LTIR players or out of the league now. But:
Buff was one of their biggest playoff performers in 2010 and was moved due to cap. He's also been a key player for Winnipeg/Atlanta since then.
Hjalmarsson was a key cog on defense. Moved in the off season of 2017 after the aforementioned finishing third in the league season. Still a top 4 guy.
Bolland was their Backlund for a long time, and was moved in 2013. Yes injuries caught up with him but still a nice depth guy that was lost due to cap.
Ladd was traded in 2011 after being a top six player with chemistry with Toews and was a top six guy for Winnipeg and a leader for years.
Brian Campbell was traded in 2011 and was a top 4 guy for a while after.
Nick Leddy was moved in 2014 and had been playing top 4 for them and was briefly a top pairing guy with the Islanders. Once he was moved they had to start rotating their top 3 D in double shifts in the playoffs because of how bad their defensive depth was? Remember the corpse of Timmonen and Rosival playing key minutes in the playoffs and how bad they were?
Andrew Shaw who was a key playoff piece for two cup wins was traded in 2016.
You specifically mention Crawford's brain being scrambled and they had to move Raanta who arguably could have succeeded him as their #1.
You cannot honestly tell me you think Chicago's window wasn't affected by literally having to move depth players every off season for years after winning cups because of cap. They would have absolutely had a better chance at winning the cup in 2011, 2012, 2014, 2016, 2017 if they hadn't had to move so many key guys. Even if you want to just limit it to their last cup win, in 2016 and 2017 they would have had a better chance and were still strong 100+ point teams.