Counter is definitely a formal channel, and customization is definitely a private imitation process.

Cartier purchased at the counter has guaranteed maintenance, but personal tailors don't.

Cartier sold by every counter has a logo, but personal tailors definitely don't.

Luxury goods like Cartier can still be bought at the counter if they have economic strength; If you don't have the financial strength and want to find a customized one, the layman can't see it anyway.