Most airlines do not provide formal guidance on wearable or inappropriate clothing, as it may be difficult to determine what may be considered unacceptable for flights.
Generally, there are no rules prohibiting certain clothing, but it is known that dirty or torn clothing and sportswear should be avoided.
The British "Mirror" website also stated that clothing bearing slogans that might be considered offensive or contain impolite language should be avoided.
Usually the crew of the plane is more lenient with Economy Class passengers, unlike Business Class or First Class passengers, you should choose clothes so that they are formal, comfortable and practical.
It should be noted that sometimes the destination you travel to can play a role. Some countries have specific laws or local customs about clothes, and an airline expects passengers to abide by it before boarding the plane.
The rules for your destination can be checked by contacting your airline operator or airline directly.