I'm quite impressed of both .NET and OpenJDK in some metrics, but it is often not resource efficient, which is something I do value.
One example of an application that works as I would expect others to do is MuPDF, Being able to open 20MB+ PDFs in 1/10 seconds on a 10 years+ old laptop.
By the way, does anyone know why Debian launches LibreOffice so much quicker than Ubuntu, Fedora or Archlinux (or any other distro I've tested with)? In Debian its 1-2 seconds, and the others 5-10 seconds. I mean it could be included extensions or how they are configured, but I'm honestly interested.
And it seem to be the start up process that differs, as putting them all in a ram-disk does not alleviate the issue, and restarting the app cuts the time in ~1/2 but equally for each distro.
My guess, as I said first is what default libraries as loaded, and possibly how they are configured. I do however find it strange that this has not been mentioned elsewhere as I've been struck bu this difference for years, when I happen to load a pure Debian install (not what I usually use).