Yellow card for taking your shirt off

[I'm With Stupid]

That’s not why though.

From IFAB.
“Additional Instructions for Referees and Assistant Referees”, the Laws clearly state: “Removing one’s shirt after scoring is unnecessary and players should avoid such excessive displays of joy.”

Which sums up football in 2021..

Well obviously they're not going to just come out and say that it's for money. But yeah, there was definitely a time by in the day where someone was running around with their shirt off after the restart because they'd taken too long trying to get it back on again, which is probably another reason.

Of course intelligent sponsors learn to improvise.