EF Core 6.0 performance is now 70% faster on the industry-standard TechEmpower Fortunes benchmark, compared to 5.0. 

the main goal of this release is to facilitate migrating existing applications that use EF 6 to .NET Core 3.0 

EF Core 3.1.3 closed issues list

EF Core adoption is very healthy 

Interactive EF Core Tutorial on Microsoft Learn