Of course, it is the actual best series ever in every sense of the word! For real, everyone has their this is the most amazing to me thing/things and Seraph of the End in it’s entirety is that to many people.
You said it about wanting more anime seasons, especially with everything branching out with the manga story and the tie ins from the prequel novels. As for the profit area, the 24 episode anime was well received more importantly Blu-ray and DVD sales were good which is quite the cash maker for anime. What was probably meant is, like for each and every manga/anime/TV show is that piracy is a hindrance to profits. Thankfully, and relatively recently Viz Media have taken steps to help with that issue!
https://owarinoseraph.fandom.com/wiki/Thread:19501
Guess the solution is easy, buy the manga, anime DVDs anything concerning Seraph of the End, A) only way more can be made with a financial reason to do so from the creators point of view and B) treasuring it in our hearts is only better by possessing the physical source material because it’s important to us. Having a copy of both the original Japanese and translated versions of which we are so lucky to also have, acquire it all. It’s a case of not saying one loves something but showing that we love it, for the right reasons since anime creators in this case look solely at the numbers.
Still, at any rate the 24 episodes are keepers forever, and the manga continues at it’s own leisurely pace, complete with the drastic “what the, that did not just happen” scenarios around every corner XD