@Anand191 Your topic title is untrue- "hosts", plural, won't leave you high and dry, one host did.
There are millions of Airbnb listings. The company doesn't go door to door to make sure all listings are legitimate and that all hosts are honest. The way bad hosts and bad guests get removed from the platform or warned about their behavior is by receiving reports from users and by bad ratings and reviews.
Nor will Airbnb share info about the actions they have taken against a user.
And if the host was ignoring phone calls and messages from Airbnb, I don't see how you expected them to be able to contact him.
No doubt this host's behavior was unacceptable and you got refunded because of it. And I understand that it was a big hassle for you.
But no one forced you to move to a hostel situation where you were in danger of being exposed to COVID. I realize it would have been more expensive, but you could have booked a hotel room, which is what most people who wanted to be in a pandemic-safe situation would have done.