The 1985 Filmation She-Ra: Princess of Power and the 2018 Netflix She-Ra and the Princesses of Power are nearly different shows that happen to share characters. The 1985 original was 93 episodes of broadcast syndication in the Saturday-morning slot, with the structural constraints of the era (each episode a self-contained adventure, low budget, narration moral at the end). The 2018 reboot is five seasons of serialized streaming, with the structural assumptions of contemporary prestige animation (multi-episode arcs, character interiority, explicit queer representation, willingness to interrogate the show’s own premise). Same cast, completely different shows. Both worth watching, neither replacing the other.
Catalogue source: heman.fandom.com (CC BY-SA 3.0) and contemporary industry coverage.