Hello, Anon.
A preposition is sometimes the best word to end a sentence with. (See what we did there?)
That is an old grammar myth that continues to persist.
A sentence can end with a noun, verb, gerund, adjective, adverb, or a preposition, but you won’t come across too many sentences that end in a conjunction (and, or, but, etc.).
(David Tennant GIF source: Reaction GIFs)
“…but you won’t come across too many sentences that in a conjunction.”