No. At root you read and write the game's memory. Most aimbots just read the memory to get locations and call the game's own methods to adjust the aim from their injected dll. Barely any actually bother reading the screen, it's horribly inefficient and limited.

I've used and written a ton of bots that read the screen, sometimes it's the best option.

Ditto, but with manipulating the game directly either through memory reading/writing, dll injection or packet sniffing.

Can you give some examples where screen reading was more effective?