I am not sure why a C# dev would use Rider other than personal preference. But for a long time Visual Studio was genuinely terrible for F# and Rider was clearly superior: MS seemed to prioritize new features and .NET fads over stability and performance, and F# development had the worst resulting bugs. One of my projects from 2018-2020 couldn't even be opened in Visual Studio without crashing or freezing.

Sadly this has changed: JetBrains does not seem to care very much about F# these days, and Rider has similar bugs to what Visual Studio had in 2016-2020. It is a bad option for F# developers.