MPL pros threw a straightforward Omnath shell together on day one of Zendikar Rising, and that list proceeded to run roughshod over tournaments with very little refinement until it was eventually banned
DFCs do come with several costs in production and logistics, so we want to be careful not to use them too much, but they had so much design space and were so popular that there was a big draw to use them
I also am running all of the mythic rare Elementals found in Modern Horizons 2
Twice last year, it confirmed it would be printing more cards, once in a general statement, and once for the Eevee-focused Prismatic Evolutions, and while that is certainly true, the supply still far outweighed the demand
Rockets Sneak Attack is still a better card, but Cyrus is a bit more flexible in that you are not reduced to Trainers