> ... linux based OS ...

The differences WRT kernel between various Linux distributions are likely not significant enough to matter for the overwhelming majority of users.

Unless you have "non-typical requirements", pretty much any of them will almost certainly be "good enough".

(Personally, my preferences are OpenBSD, FreeBSD, and OPNsense, in that order, but I'm weird. If I had to choose something built on Linux, OpenWRT would probably be the one that I'd reach for "by default".)