The existence of Troy was once considered a myth.

You say Troy was considered a myth as if it were an absolute, it wasn’t, it was debated among scholars.

Fact is German archaeologist Heinrich Schliemann was one of those learned people that didn’t think it was a myth, and in fact did locate and excavated a city matching the descriptions.

That’s how science works, things generally tend not to exist until there is proof or record of their existence, science doesn’t default to things existing until record of their non-existence emerges.

You seem to have missed the point entirely:

The scientists who considered it a myth were completely, utterly wrong. I think it is perfectly healthy to have skepticism about scientists who wage war against "myths".

See also the long fight against the "myth" of lead poisoning, amongst dozens if not hundreds of other examples.