It’ll come to all trades eventually. It started many moons ago with Gas, then moved onto electrics with the introduction of Part P of the Building Regs and the sudden emergence of the associated governing bodies (NICEIC, NAPIT etc) they have tried to bring it in for Plumbing but failed yet a few Manufacturers have stated that such and such item isn’t covered by a warranty unless it was installed by a City and Guilds/NVQ Qualified Plumber which is absurd when you’re talking about a Tap. I can’t see it making it’s way into the mainstream for Tiling for a very long time. It’s a money making scheme, nothing more.