If I clicked download on some screensavers, I would never think it had downloaded _4K@240FPS resulting in 47 GB of lost disk space!_ The fact that a big warning doesn't come up with this fact makes it even less excusable.
It's like if I went to the dentist for a filling and received a bill for 1k because "you know, those titanium fillings are expensive". Who asked you for titanium you lunatic?!
You're conflating a "one way door" with a "two way door" here. The permanant loss of money is a one way door you can't undo. Opting into a screensaver is a two way door you are a few clicks from undoing.
It's like if I went to the dentist for a filling and received a bill for 1k because "you know, those titanium fillings are expensive". Who asked you for titanium you lunatic?!