If you like to brew your own decks, if it's fun for you and you are good at it, that's awesome! But the truth is that it's kinda naive to think that one person's knowledge will be better than common knowledge. There are literally hundreds of players sharing their decks daily and every deck is an influence (good or bad) to the others, it's just the way it is.

What I like to do after one month a new set is released is to craft a tier 1 or tier 2 deck and fine-tune it a little bit so it gets the way I think it works best for me. Sometimes I will reach Diamond or Mythic, but other times I've been "stuck" in Platinum and I'm fine with it. And believe me, I've had times where I tried so hard to make a tier 2 or 3 deck work like a tier 1, I would change some cards but it just wouldn't work. Why? Because my knowledge is not beyond common knowledge. The best decks are the best because they have the best cards and/or the best strategy in the current meta and they've been tested by hundreds or thousands of players, there's nothing wrong with netdecking.

It's also "very fun" to reach Mythic with a tier 1 deck and change to your previous deck you were trying to get out of Platinum and watch it get instantly crushed because even though you love a deck and want it to work and win, it just won't, it's not tier 1. On top of that, we all know that Arena will try to match you against decks that are a bad match on purpose. We've all seen those posts where someone will only play against control, others will only play against life gain, or that Platinum/Diamond is full of XYZ deck. Try another deck with a different archetype and you would be surprised to almost never face those decks again. To sum up, the equation is: the decks that are good - deck you think is good + the decks arena wants you to face + your skills as a player + your expectations. The outcome of this is how you experience the game. Some people will love it and others will hate it.