Is Blue Exorcerist mostly adapted now? Why did it get 3 new seasons?

I watched the first season quite a while back, and then the second season which was the kyoto arc which I found it a bit wierd as a soft reboot.

I then find out there was a third season in which I was putting off for some time now. I go to pull it out to watch finally, but then I saw it had 2 more seasons so 3 seasons in total I did not watch yet?

I found those odd considering the hiatus it had for some time that it was able to spring up 3 more seasons? So is it mostly done now or is more seasons coming?