> Every employee should see their role as temporary. This isn’t the lifetime employment pension days anymore. I see many opportunities for employees to walk away as a positive.

Good advice in general, but not a hard rule. There are roles where you need to expend a lot of energy learning proprietary stuff (processes, languages, frameworks, business rules). If you're in one of these roles it can give you a ton of leverage, but tread carefully around egos (you could get fired out of spite if you flex too hard, and maybe that's fine, but generally it's lose / lose).