Thank you! With all the pushing from the GU team to incentivize people to stay in Mythic, I think the playing field has leveled out quite a bit with many less-optimized decks being played. As with any TCG, although I do believe that I am pretty good with my cards, there is always luck involved in the matchmaking (if I faced 20 Board Wipe Deaths, my WR would probably be something like 10 wins or so), and the luck of the draw.
After 8 weeks in Mythic, I do feel like anyone with a decently formed deck at the 0.01 - 0.10 ETH range can probably score >=16 wins rather consistently with a bit of luck. You can take a look at @yeetmaster 's posts - he has done 19 wins two times in a row with much cheaper decks.
Cheers!
Luck of the draw can definitely not be underestimated.. I think that's honestly the main difference between budget decks in mythic and more expensive ones: consistency. Very possible to get a good WR with a budget deck, but keeping that up consistently is harder than if you had a more solid deck. New system does make it more welcoming for cheaper decks though: plenty of packs to be earned and legendaries from 15 wins, as opposed to 17 (if I remember..).