Fandom Friday: How can iCarly share the same universe as Henry Danger?

I don't understand how iCarly can be in the same universe as Henry Danger on Nickelodeon. On Game Shakers, the characters Triple G, Hudson, Babe and Kenzie are really big fans of the iCarly TV series to the point that they snuck into the hotel room of actor Nathan Kress (who played Freddie Benson on iCarly) to ask him questions about the show on the episode Game Shippers.

Game Shakers season 2 episode 17: Game Shippers

Now this is where things start to get interesting because in the iCarly universe, there was a crossover episode with the Victorious TV series which eventually led to the spinoff show Sam & Cat starring Sam Puckett (iCarly) and Cat Valentine (Victorious). On Sam & Cat, they're friends with a character name Goomer, who is a slightly dim-witted and naive mixed martial arts fighter. Somehow Goomer ends up as the sidekick/minion to villain Frankini on the Henry Danger TV series. Then to bring it full circle, Henry Danger had a crossover with Game Shakers.

So, how can iCarly be a TV show but also share the same universe as Henry Danger? This makes no sense and I'm probably over thinking it but it is interesting to think about.

iCarly and Victorious

Goomer (Sam & Cat)                                                                                  Goomer (Henry Danger)