For an anime series that's run as long as Fairy Tail, death is an inevitability. No series can go on that long without losing heroes and villains, which might cause some fans to leave the series. Some may even argue that the series should have had even more death scenes, such as Gajeel's moment with Bloodman during the final arc.
Source:https://www.cbr.com/fairy-tail-saddest-deaths-ranked/