No one with brain will implement 5e rules first and implement such a homebrew rule second and make all the work useless.
If your point is to create a D&D game with awesome homebrew rules to overhaul the experience, I guess that's what everyone should do^^
Not sure any DM create his own rules before having tried the RAW.
Their mechanics, rules and wishes are awesome and could really enhance D&D but as they are implemented, they altered the experience way too much... leading first of all to very poor combats in which the only real tactical choices related to these homebrew rules are "fire, ice or poison ?"
(Backstab and High ground are so powerfull and so cheesy that they're not really choices... Everything is balanced considering we'll always use them).