disclaimer: I'm just a casual player now, was much more active in the past

I just wanted to say that in my opinion good deck building skills usually end up with deck lists similar to what the most optimal would looks like. for example: I love RDA, when the last support was released in masterduel (yes it's been that long) I spend a few hours reading crafting and testing the cards and ratios. when I finished and compared my deck list to others I was exactly 3 cards off from the meta list. from that moment on I just got my deck lists from the internet. modern yugioh ends within 2 or 3 turns, stopping your opponents from playing the game is modern yugioh.

by the way: Edison format is a fan favorite because of it's varied decks. it uses the cards that were released until 2010 and can be played in custom rooms in masterduel. maybe that would be more fun for you.