What is the connection between the two?
Almost all software depends on other software. At the very least, it depends on the clients software. Which means you can’t ignore what Chrome or Safari changes for example.
They just aren’t chattering away about it.
There's web tech from decades ago that still works almost entirely the same. If you stick to the most beaten path, you can really profit off it.
A lot of "legacy" software is still kicking because of this. Well... it works and solves the problem. And we can update it too, if we just stick to what we're doing. There's Perl scripts decades old still chugging along on servers all over the world. There's Windows applications written in the 90s that work pretty much exactly the same and are still updated in C++.