Really the primary disadvantage these days is that you won't be able to access that part of your bank balance (often lower than most credit limits) for a bit of time until the bank either issues you a temporary credit or the dispute is resolved. This happened to me once in the earlier half of the 2010s and it was frustrating to have to wait for my balance to get restored.

There are enough banks in the US nowadays that cover debit fraud that any bank that doesn't do it will really stick out like a sore thumb and eventually lose their customers.