@Kanami-chan There's a few Japanese web novel blogs that pump out new isekai every day. Most of those that have any amount of coherent story line eventually get turned into a light novel. After that point its only a short hop over to the manga world. So to answer your question, the reason why there seems to be a new one every day is because there is a new one every day.
The big issue is that people are starting to confuse Isekai, Tensei (reincarnation which doesn't need to be isekai), and Fantasy to the point that someone told me that Berserk was their favorite isekai.
@degenerateafro Must be those people who stubbornly claim everything that isn't taking place on earth as isekai, because they took the term way too literal.
@Kanami-chan Yeah, just like any shounen and shoujo manga.
@Kanami-chan Did you know that you can select tags to exclude from the frontpage, latest chapter updates, and chapter lists. Go to https://mangadex.org/settings and search for "Exclude tags:". In there you can checkmark the Isekai tag and then click save.
@ices what tag to use to exclude chapters that are parts (but not exclude the final part), reuploads that already exists (not exclude if its a reupload from something that was deleted), and other such pet peeves?
@Guspaz i say if you want to re-do it, go for it. the early ones done by whimsubs are especially of low quality since it was from back when they just started in batoto (so thank god their quality has improved over time)
Dumbledore+Gandalf
Well, yeah its a nobrainer when the author/player uses two notable grand wizards in their own stories.
Not to mention they look very similar too.