@Michele511 The security deposit on Airbnb is basically a joke. They do not charge or hold the funds and they don't pay you for any damages without you first trying to request the money from the guest, then if the guest refuses, you have to go on a long song and dance, submitting photos and receipts and argung with CS, and likely still not getting anything.
There are other more concerning reasons not to host long term through the platform- in most places, any stay longer than a month puts the guest into the realm of landlord/tenant acts. You could have a terrible time trying to evict them if you needed to. Especially now in this COVID crisis, when evictions of any kind are pretty much being disallowed.
Long term renting, to anyone you don't already know and trust, is best done in the traditional way- a lease, a real security deposit, the lanlord requiring references and work history, etc.