It allows you to just build things rapidly without worrying much about patterns/naming because once your vague ideas solidify and you realize where you went wrong, it's really easy to just Ctrl+Shift+R and make any codebase-wide adjustments instantly.
It's also great about picking up sub-optimal implementations or patterns with helpful warnings, and you just Ctrl+. to have it auto-fix for you. Using these Rider features combined with Github Copilot, I was able to pretty easily learn intermediate level C# because it's like having a mentor working along side you.
edit: been using Rider on Linux since a few years now
No, it uses Resharper as the backend.
But I use a .editorconfig tuned stylecop and roslynator on all projects so maybe that overrides some defaults.
Mind sharing which Java style rules are you seeing ?