Why do we need babel/swc plugin for SSR?

Effector plugins inserts special tags - SIDs - into the code, it help to automate serialization and deserialization of stores, so users doesn’t have to think about it. See article about sids for more info.

Why do we need to give names to events, effects etc. ?

This will help in the future, in the development of the effector devtools, and now it is used in the playground on the left sidebar. If you don’t want to do it, you can use the babel plugin. It will automatically generate the name for events and effects from the variable name.