Yeah, I definitely feel this some days. I've just moved over to C# from Java because I'm bearish on Oracle as a vendor in general, I find C# great and impressed with Microsoft's efforts as a vendor with what they've done with .NET Core.
I have love for Java, but I gotta say it mostly is because the ecosystem is pretty fantastic. So much open source stuff for so long means it's all just there and it all just works. There are some gaps though.
.NET ecosystem isn't bad. It's pretty good. There are some phenomenal libraries. But sometimes the gaps are painful. The lack of an open source (read FREE) integration framework is a big one for me. There is BizTalk but that's commercial and probably expensive. Same with scheduling libraries. HangFire looks great but it's paid. A lot of the really high quality stuff you have to shell out for which when you're just hacking in your own time is not feasible. That being said there are open source libraries and some of them aren't bad. Lots of great stuff in general.