They are separate because the Netflix series is a reboot, not a continuation.

The Netflix seasons were NOT a different show or reboot. The same goes for the new season being produced now. Although Netflix gave them additional titles such as "The Return" and "The Gauntlet" they are referred to by production partners Shout and Alternaversal as seasons 11 and 12, and the new 2022 season as season 13. These new seasons are not reboots or reimaginings of the show: they are deliberate continuations of the original show headed by its original creator. These should not be listed as separate shows but should be merged into a single entry. I work as a Mod for their Twitch channel and am not only closely connected with the fandom but also get to peek into the inner workings from time to time. I can assure you, despite the decades-long gap between seasons, this is considered a single show within the same continuity and should be listed here as such.