My STR's are doing great. Actually my numbers are the same the last two years despite all the rumors of an Airbnb bust. I believe the same as what @Nathan W. shared. It's a business. Just like other businesses, some succeed and others fail and it boils down to management. Also, no one cares about your business more than you do.
I also agree with @Michael Baum, STR in the right area at the right price will do well. One reason I bought my Oceanfront condo in Myrtle Beach is because it has all the criteria to do well. 14 million people visit here each year. That's a lot of demand. Second, it's the beach! and it's an easy drive from some major cities like Charlotte, NC. Third, the price of entry is still relatively low. These are all key factors for me.
Expectations are the big factor now. As others have said, if you think you are gonna just buy a property and start printing money, that probably isn't gonna happen. That's what math geeks like me enjoy showing people. The math never lies.
Numbers are numbers, business is business, and expectations have to match that.