Except by that criteria (the historical record), the Assumption (a.k.a. the "dormition of Mary in the Eastern churches) was celebrated liturgically in both the Latin west and Greek east by no later than the 7th century. And this early, widely-held belief comes with no record of dispute. (That Munificentissimus Deus in 1950 made the long-standing belief into dogma doesn't negate the historical fact that it was then and before a long-held, uncontroverted belief.)
By contrast, the notion of a "Pre-Trib Rapture" is unknown till the 18th Century, and was then and now controversial, as it contradicts accepted Christian teaching of many centuries.
As to Scripture, the Assumption is not in any way contradictory (the Bible doesn't speak explicitly of Mary's final days) and is harmonious with several verses about Mary as well as the Scriptural anti-types (Enoch and Elijah).
By contrast, as has been pointed out earlier on this thread, the very verses held up in support of a Pre-Trib Rapture contain within them items which contradict that notion.
Correction: Enoch and Elijah would be the “types.”
Lots of people believe wrong things for a long time and it doesn’t make them right.
You can appeal all you want to circumstantial evidence and practices and traditions, but the fact of the matter is there is ZERO support from Scripture for the event and just because the Bible doesn’t say something didn’t happen, doesn’t give anyone the right to make stuff up and claim it’s true just because it isn’t specifically mentioned as not happening in Scripture.
At that point, then Mormonism has lots of stuff that they claim happened that Scripture doesn’t outright contradict. Are we obligated to take that as fact to just because they claim it?