Is the increase in sequels blocking the sun for new (good quality) anime?

I rather see less anime , but more of them get finished then a big dump of incomplete shows.

Well, a sequel season takes up less resources than a long running anime continuously airing for hundreds of episodes as it happened in the past.

And what's the alternative? "If an anime adaptation can't adapt the entire source material in 1-2 cours, it must be left incomplete because we need to make room for new anime!" You won't find many people agreeing with this.

@Nirinbo alternative is more anime with shorter run which will finish without sequel need, or at least not so much seasons to end the story.

Sequels are a safer investment, especially nowadays where studios don't need things like fillers, and it gives the chances for a complete adaptation which wasn't always possible back then, and original anime as much I like them. It is really easy to flop because the writing team has to start something from scratch, which isn't an easy thing to do. As for remakes, I am fine with a remake if it is an improvement to the original adaptation and not just the old thing or a worse version of it with modern animation and visuals. Also, a quality studio doesn't always mean that you will get a quality adaptation. Most studios can produce good and bad series. The environment of the production and the people who work on the said production are more determining factor than just the studio.

While it's true that some titles get milked to death, some stories require a certain length for proper execution. Not everything can be adapted in a 12–24 series without sequels and the ton of rushed adaptations is a proof of that.

@Stanis150 All these sequels aren't original anime, but adaptations of manga or light novels. Rather than blaming anime production committees for wanting to fully adapt them, you should blame the serialization business model of manga and light novels that encourages authors to prolong their works for as long as possible (and in this case I might agree with you).

@pk8list you don't need to adapting anything if there are no any source material))

An industry can't survive just by throwing balls on a wall and hoping that they will stick. It would be nice to have more original anime, but due to the inconsistent quality and reception of these series making them, your main focus is playing with fire financially and also not adapting anything to a lot of industries negatively, because the majority of anime and a lot of other media are adaptations which have as a purpose to promote the source material and/or to sell merch like Nirinbo said above a lot of the blame should go more to bushiness models that exist clearly for milking than the productions themselves.