All plugins can be disabled with some lose of functionality,
so this is up to you to decide.
Plugins which provide a great deal of functionality such as an entire language
support should be prime candidates.
A user testimony
says:
Go to preferences > plugins > and disable everything you don't need. I disabled "Android APK Support", "Android Games", "Android NDK", "App Links Assistant", "CVS", "EditorConfig", "Firebase " (all of them), "GitHub", "Google " (all of them), "hg4idea", "Settings repository", "Subversion integration", "Task management", "Terminal", "Test recorder", "TestNG", and "YAML". Goes real fast now.
Another article
lists:
Android APK Support,
Android Games,
Android NDK,
App Links Assistant,
Copyright,
Coverage,
CVS Integeration,
Editor Config,
Fabric for Android Studio,
Firebase (App Indexing, Services, Testing),
Github,
Google (Cloud Tools Core, Cloud Tools for Android, Developer Samples, Login, Services),
Markdown Support,
Mercurial integration,
hg4idea,
Settings repository,
Subversion integration,
Task management,
Test recorder,
TestNG-J,
YAML.