Warning: The following contains SPOILERS for Superman and Lois season 2, episode 3, "The Thing in the Mines."
The central storyline of Superman and Lois season 2 ignores the existence of the Arrowverse Justice League, even as the show's characters wish for someone to help Superman with a threat he can't handle alone. This has been a continual problem for the series, which has largely avoided any reference to the larger Arrowverse, despite being a Supergirl spinoff. While it makes sense, logistically, that the other Arrowverse heroes couldn't be brought into Superman and Lois as easily as in a comic book storyline, the show has exacerbated the increasing distance between the various CW superhero shows in recent years.
While it was not officially given the Justice League name, an Arrowverse team made up of the World's Finest heroes of Earth-Prime was established in the final episode of the Crisis on Infinite Earths crossover event. After bringing several heroes together for a memorial service for Oliver Queen in an abandoned STAR Labs hanger, The Flash revealed his intention to turn the facility into a base of operations, so the assembled heroes could "gather if anything ever happens again." The episode ended with The Flash unveiling a round table, with chairs bearing the insignias of each hero—including one for the fallen Green Arrow. This promised more Arrowverse crossover events, but the filming restrictions brought about by the COVID-19 pandemic curtailed these plans. The Arrowverse Justice League wasn't mentioned again until The Flash season 8 Armageddon event, which made reference to an off-camera crossover featuring Felix Faust.
Superman and Lois season 2 ignored the existence of the Arrowverse Justice League, even as it introduced a villain who was precisely the sort of threat the team had been forced to face. To complicate the matter, Superman's powers began failing him at inconvenient moments, as he began experiencing overwhelming visions of destruction and panic attacks that coincided with a series of earthquakes centered around the Shuster Mines in Smallville. Despite a number of teasing red herrings that the earthquakes were the work of the villain Doomsday, the Superman and Lois season 2 episode "The Thing in the Mines" revealed the source of the earthquakes to be "a bizarre version of Superman."
"The Thing in the Mines" made multiple erroneous suggestions that Superman's options in facing his doppelganger were limited. Early in the episode, John Henry Irons offered his help in investigating the earthquakes, despite having promised his daughter, Natalie, that his superhero days were behind him. When both Clark and Lois reminded him of this promise, Irons asked the Man of Steel if there was "anyone else you can go to right now?" The Justice League was not mentioned as an option.
Later in the episode, they called upon Lois' father, Ret. General Sam Lane, for advice. After the Bizarro Superman's nature was exposed, Lane insisted that they had to contact his successor at the US Department of Defense, Lt. Anderson, and bring in his Supermen of America team. When Clark protested this, having hoped to avoid turning to Lt. Anderson for help after their falling out, Sam Lane told Clark that he couldn't try to take on the Bizarro Superman alone. When John Henry Irons assured Sam that Clark wouldn't be facing the monster alone, he asked if Irons really thought "the two of you will be enough?" Again, the possibility of calling upon the Arrowverse Justice League was ignored.
It makes sense that Superman and Lois wouldn't want to undercut their heroes by bringing in other characters outside of a special event. However, the fact that the series seems to be going out of its way to avoid referencing the larger Arrowverse or acknowledging any link to Supergirl and her series only serves to make the characters look stubborn or stupid for not considering the possibility. It also seems like it wouldn't take much effort for the series' writers to fabricate some excuse for why Team Flash or the Super Friends couldn't be called upon to help Superman in his time of need.