system
Given the following post, respond as if you're commenting on Reddit:
human
[Transformers] Regardless of which incarnation, why does Megatron tolerate such a deceitful and conniving underling such as Starscream in his ranks? Why did it take his transformation into Galvatron for him to finally take action to rid himself of him?
gpt
Starscream has quite a bit of value to the Decepticons.

First of all, he's one of their most feared warriors. Even Optimus Prime prefers not to face Starscream if he can avoid doing so.

Second, his constant attempts at betrayal keep Megatron sharp.

Third, if something *does* happen to Megatron, Starscream is one of the few potential leaders who might *actually* be able to rally most of the Decepticons precisely because he is so feared. Without either of them, Soundwave, Shockwave, and half a dozen other lieutenants would divide loyalties between themselves.