I wrote this in 2012 - almost exactly ten years ago - and it remains true.
Looking at freebsd.org right now I see that my options for production, release systems are 12.3 and 13.0 ...
... which means that if 12.1-RELEASE came out at the end of 2019 and 13.0-RELEASE came out in April of 2021, you had all of 16 months to make investments in the 12 branch before it was hopelessly passe and all queries regarding it would be answered with:
"That's fixed in current ..."
The 4.x nostalgia is justified: it was polished and polished and polished over many years and many organizations were incentivized to invest in that branch
Looking at freebsd.org right now I see that my options for production, release systems are 12.3 and 13.0 ...
... which means that if 12.1-RELEASE came out at the end of 2019 and 13.0-RELEASE came out in April of 2021, you had all of 16 months to make investments in the 12 branch before it was hopelessly passe and all queries regarding it would be answered with:
"That's fixed in current ..."
The 4.x nostalgia is justified: it was polished and polished and polished over many years and many organizations were incentivized to invest in that branch