Sheer ignorance and not paying any kind of attention. People are parasitized by tiktok you think they’ll notice a subtle entity?
Start taking responsibility for their own energy, learn emotional control and start protecting their energy. half the battle is realizing there’s a problem, the 2nd half is standing in your own power and knowing you’re easily capable of dealing with it. You decide it’s not happening and so it is.
Humans are powerful entities, with onboard nuclear power stations called a human body. Not just any spirit is capable of piloting a human incarnation - the lesser entities can’t or they’d incarnate. It’s actually ridiculous how powerful we are - why else do you think lesser beings want some? Our issue is we forgot who we are and how to do it, and we allow our systems to get gunked up with stupid things that don’t matter, including lesser entity possession and parasitism.
You can see more strident techniques for dealing with stubborn parasites here: Forum Tutorials: Parasite Collection or use the search with more specific keywords.