Yeah, Reforged was received very poorly so they basically end of life'd the franchise.
There is a thriving community with a couple different choices for servers to play on. So I'm sure there's a fix for your mouse speed issue.
Check Twitch for people streaming it: https://www.twitch.tv/directory/category/warcraft-iii
Grubby, one of the early esports stars, still streams it regularly and hosts his own for fun tournaments with other streamers.
Reforged was received poorly because it was a lazy half assed job that was a blatant cash grab. Not because culturally we have moved on and the game has aged beyond being fun
You probably knew this, but wanted to make sure others knew that the reason they ended the franchise is not because there was no market, but instead it was pure unadulterated greed that led to that situation. In an alternate reality they would have actually done the remake justice and there would be a lively competitive scene