I have far fewer years in the kitchen than you but I recently posted a similar question on reddit's cooking forum. The overwhelming answer is, there is less diversity in food than one would think. Even if you look towards foods like African influences, you'll find that Arab and then Indian.. it's all so very similar. Nothing new under the sun. French techniques run rampant in other cuisines. We really are limited when it comes to ways to "cook" food.
I'd ask in 30 years of cooking what cuisines have you pursued? Nordic was another that came up as different. Asian also.. beyond what we know as typical Asian. That is.. there are many variations and they are not necessary similar.
What I've been doing as a way to get out of the kitchen and continue to explore food is revisit artisanal methods of bread making, pickling, curing meats, etc. There is an entire world to delve into that while not technically involving a finished dish.. certainly affords people whom are hungry for new and exciting challenges their due projects.