You are asking questions in grey areas.
Here I am talking about my experience on Koh Samui - it may be different depending upon the different local authorities. (A bit like 'local' immigration rules.)
The villa is not a hotel but the local authorities change the heading from Hotel Licence to Villa Licence.
The document is the same thing though.
The properties are not registered as hotels but just forced to go by the same rules as hotels. eg smoke alarms, fire extinguishers, safety ring for pools etc etc.
When we first applied for villa licences years ago, our company accountant said that legally, Villa Licences do not exist. So we went through an agent.
Some owners used their own accountants.
As they are not registered hotels, I would think that they do not pay hotel taxes.
The income and taxation is down to individual owners.
Our company does not get involved in the villa rentals/AirBnb.
How can it be a level playing field.
It would be like ice hockey players playing against a golfer.
Many hotels are part of larger organisations.
AirBnb properties are mostly owned by individuals.