I don't run SDs for anything important. I've had a dozen RPis in my home rack alongside the "serious" hardware so I've killed my fair share if microSDs.
I'm not very familiar with OpenBSD, have run FreeBSD for a while, would certainly be fun to play around with a router based on a standard OS and not have to worry about proprietary updates like with the EdgeRouter any more.
That was my first and last important thing running off SD. And I too have had a few uSDs die in RPis. Though at work I have a Beckhoff PLC in a machine with a uSD running in a control cabinet. Still running fine after 2.5 years and I've not heard of issues with them. I'll have to find out which brand it is.
I run both FreeBSD and OpenBSD. FreeBSD for recently built home server as it has first class zfs support, bhyve works well, and excellent docs. OpenBSD as I know a few hard core users, and I've been using it on old hardware for years (have an imac G3 running it :). VPS for webcrap. OpenBSD is clean and they have good documentation as well. At the bottom of the following link is the pf router how-to I want to give a go, https://www.openbsd.org/faq/pf/
If and when I buy a new APU I plan on running OpenBSD and learn to setup PF proper and roll my own router (A friend runs such a setup and loves it). At this point I just want a standard OS.