I am sure there are good reasons for not using a framework for WebFig, given it needs to run on tightly memory constrained platforms.
Perhaps MikroTik has developed their own internal framework and guidelines.
No matter what you do, things get outdated. Look at the Dude. Is there anyone left at MikroTik that understands its code base?
I did get a chuckle out of the xkcd cartoon @Joni posted here
And it reminded me of programming languages like PL/1 (i.e. a universal language)