I used FreeBSD before I used Linux. It was still really complicated to set up at the time. I can’t speak to modern versions. I also used openbsd more recently to make a router out of a sun ultra 5 I trash picked. Learning pf and seeing up a router all by hand was a good learning experience. Then the hd crashed and I didn’t have a backup of my configs. I didn’t have enough ambition to start from scratch, and there are plenty of modern distros that are ready made routers.