I think you are over simplifying the complexities involved with this analogy . Backpack seems to break a lot of laws explicitly. I would rally love to see what the founders have researched about different destinations and airports.

Many (if not most) of AirBnB's major markets explicitly forbid short term rentals without a hotel or bed & breakfast permit and associated taxes, yet AirBnB lists and drives business to them seemingly indiscriminately without so much as asking for such paperwork.

What's the complexity? Airports and felony charges instead of evictions and injunctions?

well at least in germany you are supposed to declare this income. but that is the same with any form of rent that you gain based on your property. so it doesnt matter if i rent out a property that i own for the whole year via a classified ad in the newspaper or for 1 week via airbnb.

declaring income is one thing, but hotels in most areas collect specific hotel taxes levied by a municipality, and airbnb people aren't collecting and remitting specific hotel taxes.

The typical AirBnB location is not a commercially-zoned, licensed hotel. Municipalities can update their laws to be more relevant if they feel they are losing tax revenue.

Municipality tax relevance is a far cry from international laws that are already in place.

"Municipalities can update their laws to be more relevant"

Or... people could comply with the current municipal laws and not run commercial enterprises in non-commercially-zoned areas, or even just respect whatever HOA or landlord agreements they are party to.

Again, enforcement is up to the municipality, and Air bnb is cooperative: https://www.airbnb.com/help/article/481

HOA and landlord contractual agreements are not the same as municipal laws and are frivolous to the conversation about international import laws. Mentioning them makes it seem like you're scraping for excuses to attack air bnb.