Yes, entirely tangential. As you say they are points in space around which material behaves as though there is an extremely compact massive object. The limits on the mass and radius leave us to the conclusion that these must be black holes because our current theories allow for no other conclusion.
Our current theories are pretty good at predicting the vast majority of the phenomina that we see out there; so we sort of have to trust them on this. But that doesn't rule out that something else may be going on.
And this is always the way it is with Science. Science is a negative discipline, i.e. no theory can ever be proven correct. All a scientist can ever do is disprove a theory -- but never prove one.
>From: TheGuyThatLookedI... at 02/20/23 14:10:19 on wss://relay.damus.io
>---------------
>From what I have seen, the evidence of them existing (as in points in space with extreme gravity pull) is pretty tangential, mostly relying on theories and suppositions.