number of "coats" of paint

I ve not been painting cars for a long time but the guy i have learned from has about 10 painting certifications and does great work and uses the newest tech in paint when he can. Does the idea of a LARGE number of coats really still "make" a better job or is that restorers using old technology
im not sure someone saying i have 15 coats of clear makes me want that car ( i have bought cars with clear falling off) just a question for Pro body paint guys