I would say I kinda sorta maybe disagree with that one. Spoilers for anyone who hasn't seen the series finale of the show but once he meets Stan Lee and says that he never thought he got any breaks but he's realized now that it's time to be happy and that he likes himself and his life, that's the end of an arc for that character. Stan even says that he sounds nothing like the guy he's been writing all these years and Peter responds "I suppose we all have to grow up sometime" and when that happens, once that character finally accepts the good in his life rather than focusing on the bad and "grows up" then that is kinda the end of the spider-man that we all know about. It would be like if Bruce finally got over the death of his parents and decided he wanted to lead a normal life and have a wife and kids. The show ran for 5 seasons which is no small feat and the series finale wrapped up it's main characters story. Now obviously if they were getting another season or two it may not have ended that way but I think they got a lot of mileage out of the show. Now spectacular on the other hand, that's a different story