well, if you say so
When it comes to manga, each type of Saint Seiya fan gets to have his share of the cake:
Saint Seiya - Next Dimension (total of 16 expected vols) is the official sequel targeting the teens/adults who read the series during it's initial run.
Saint Seiya - Episode G (20 vols + 1 Extra), it's sequels G Assassin (16 vols) & Requiem (4 vols - ongoing) is the seinen version of Saint Seiya targeting kids/teens who grew up with the manga and now adults who want a more matured up version of it.
It's my personal favorite

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Saint Seiya - The Lost Canvas (25 vols), Anecdotes (Gaiden series - 16 vols) & 1 Extra Bangai-Hen proposes a more modern approach to Saint Seiya appealing to readers who are familiar to works like Black Butler, Pandora Hearts and D.Gray-Man. It is to date the most successful Saint Seiya manga spin-off that got to appeal to the mainstream manga readers.
Both the G series and Lost Canvas, despite referencing the original manga and taking into account the OG manga's events, take place in their own time-line branching into their own future - so there's no plot-holes involved.
Saint Seiya - Saintia Sho (16 vols) + Extra (ongoing) was advertised as a shoujo version of Saint Seiya, focusing on a full female cast - it's however, in my opinion, the weakest spin-off and the one that had the lowest sales around 10k per vol if I remember correctly.
The author, tries way too hard to insert herself into the original timeline of the manga and there's too much fangirl fanservice, focusing on the mangaka's favorite legacy male characters with the plot barely taking off. At the half way point, the heroines had become spectators in their own manga.
It's incredibly beautiful and well illustrated though. It just needed another person to write the story.
It is regarded as an Outside Story or Side Story.
Saint Seiya - Dark Wing (3 vols ongoing) this time targets the 2020 manga reader crowd with an isekai setting and a lighter tone to it. I'm not the target audience but it seems people like it quite a bit?
Over time there has been other smaller manga projects like the Saint Seiya Omega manga that served as a companion piece for it's 2nd anime season, Time Odyssey (French manga or manfra as they call it) & the Golden Age one-shot - project for the manga's 30 years involving the 3 mangakas (Okada, Teshirogi & Kuori) working on the spin-offs.
Since Yun Koga also participated in the Golden Age project, her manga - Kurumada Suikoden ~ Hero of Heroes could also be considered a sorta Saint Seiya spin-off.
Point to be noted - all of these mangakas have gotten the blessing of Masami Kurumada, Saint Seiya's creator, to do whatever they want and take the story in the direction they seem fit and we know he personally requested Okada and Teshirogi to work on his franchise.
Kurumada is, himself, currently writing & drawing Saint Seiya - Next Dimension and on his preface message on the latest vol, he mentions that even after 50 years of career, he is still gonna continue writing!
Over the last 20 years, we've gotten a total of over 100 tankobons worth of new content!
Yeah I remember that there was always something new, like 3 new mangas at the same time, it was great !
Oh, the blessed time when Lost Canvas was coming out weekly.