^^^ This is all true.

On our previous Santana, that had a replacable hanger that I thought was somewhat fragile. The original hanger did not survive the initial shipping to the shop as the box fell over in their shipping area and bent the hanger. Dealer tried to straighten the hanger which left a micro crack in it. Definitely not as robust as the solid fixed hanger on the Calfees.

My cf Trek single has been with the dealer & Trek for over a month getting reviewed for a defect. No hanger issues on that frame though I had crashed it a few times.
Now riding a Specialized Tarmac single (first a SL3, now a SL4) both had replacable hangers, but I've had no issue other than to ensure the mounting screws are tight. This year at the Women's US Pro road race, the neutral support guy broke off the leader's hanger (Specialized bike) while trying to forcefully remove the rear wheel... interesting to see the deraileur laying on the ground, chain and all with the ex-leader standing there while the support guy shrugged.

I recall reading that some pro teams requested steel hangers instead of alloy (al?) perhaps to avoid the complete failure of a snapoff situation.