It's the same reason why people watch tv shows. Because it's entertaining. The only difference with anime is that there are much more creative shows to pick from rather than an overused idea which tv shows are mostly.
Insecurities? I watch anime because western cartoons are shit there's nothing good anymore except the few occasional good ones like Gravity Falls, Adventure Time, Rick and Morty etc. While anime has better visuals, music, story, animation so on and so forth. Nowadays most cartoons are just a random mess that don't follow a storyline and have the characters do random shit that 3 y/o kids would only laugh at.
A lot of things portrayed in anime would never be able to be made by western live action or animation even. Stuff like made in abyss are best shown in anime form, since the fantastical world would be very costly to create in live action.