"only" is a big word, kid. like all absolute qualifiers, it is one requiring but a single counterexample to refute.
I am not one of the big dogs on the history of science in the 20th century, so I cannot easily give you one clear example of a scientist accepting a new model after strongly supporting an old one. However: I know there have been not one but many such, and am quite certain one of the big dogs I have included as recipients of this note can easily provide names of such examples.
What I don't know is whether:
1. they will consider it worth doing, or
2. whether you are capable of accepting a factual rebuttal.
Alfred Weggener was laughed off the stage at his first presentation of his continental drift theory. Not a scientist of his age ever adopted the Weggenerian view.
Eventually, the new science of tectonics proved Weggener to be correct. All current scientists believe tectonics to be the correct answer.
At the same time all the unbelievers are now conveniently dead.