The biggest problem is how Batman and Superman are portrayed, with both of them being very serious and wanting to take each other down for similar reasons.

Source: https://screenrant.com/batman-superman-worlds-finest-animated-crossover-dcu/

Unlike characters like Batman and Superman, who each have a book that has been running non-stop since their debut, Green Lantern hasn't had one long-running series, but multiple books over the decades.

Source: https://www.cbr.com/green-lantern-dc-best-premiere-comics/