* Electron apps - VSCode, Atom, Slack, almost every universal desktop app that gets released today. Individual ports of apps to FreeBSD exist, but there is no way to automatically build Electron apps for any of the BSDs.
* Good desktop virtualization - KVM, VirtualBox (okay FreeBSD has these in theory), VMware
* First-class Docker and desktop container support (FreeBSD jails exist but there is no container ecosystem like there is on Linux)
You can still run Firefox, mail clients, vim/emacs, Unix utilities and LibreOffice on any of the BSDs just fine. They're lacking other niceties however. And that's a bad thing in my opinion - although it's mostly not the fault of any of these projects. Some people think BSD is better for lacking those options, but I can't live without them for one.
It's unfortunate: Linux and the BSDs used to have more or less the same application support. Anything Unix-y ran on anything Unix-y. There was nothing stopping you from having an OpenBSD desktop almost identical in function as, say, a Xubuntu desktop - one that looked much cleaner on the inside. But once broader commercial interest started happening for Linux, the BSDs were mostly left by the wayside in application support.