Purpose is an inconvenience
Purpose, if you choose to have one, isn't a branding exercise. It's a constraint. It's the thing that tells you what not to do, which meetings to decline, which contracts to refuse, which shortcuts aren't worth taking.
Patagonia turns down business because of it. Sweden's Handelsbanken has operated without budgets since the 1970s because of it - and has been more profitable than its peers every single year since 1972. When a CEO resisted their decentralised purpose in 2016, they removed him.
That's what commitment to purpose actually looks like.
If you're not prepared to be inconvenienced by yours, you don't really have one.