@Kevin1855 Declining a booking request affects your Acceptance rate, but that's not an issue unless you decline lots if them, which could prompt a warning from Airbnb. Acceptance doesn't factor into Superhost stays, either.
But if you can't make having reviews a requirement for requests. If you do that and it comes to Airbnb's attention, that could get you in trouble.
The whole reason that IB hosts have the option to require recommendations is because when guests IB, you don't have an opportunity to communicate with them first. The way a guest communicates, whether they answer any questions you pose in a clear and timely manner, is what hosts who don't use IB rely on to decide whether to accept a guest if they have no reviews to go on.
Hosts who are accustomed to using IB seem to put far too much faith, IMO, in guest ratings, which non-IB hosts aren't even privy to. Hosts have had terrible guest experiences with some guests who had previous 5* reviews. It's not some assurance of a great guest.
Of course if you are getting a bad feeling about a guest due to what they are telling you , their manner, or feel they are being dishonest or evasive, that is enough reason to decline a request. As is seeing that they have some past bad reviews. But simply that a guest is new to the platform and has no reviews isn't really a good reason in itself to decline them.
If you aren't aware, Inquiries do not require that you click on pre-approve or decline at all- just messaging back within 24 hours is all that's needed. If it's a Request, you do need to accept or decline within 24 hours, unless you can convince the guest to withdraw the request.