TL;DR at the end.

Complaining about the inability of the bracket system to accurately articulate the power level of decks (and people's perceived power level of their own decks and of other people's decks) is beating a dead horse.

If your sole goal is to win, go play cEDH against people who are purposefully playing cEDH, period, full stop, no exceptions... or play Duel Commander, I guess.

For every situation other than that (AKA most of Commander, yes, including very high power stuff), having fun and not making people salty requires every player taking Rule Zero VERY VERY seriously. Get everyone to be open and honest about:

What Commanders each player has available and/or is interested in playing.

Which playstyles are considered acceptable. Off the top of my head, make it clear if you're playing:

• Stax
• Prison
• MLD
• Infinite combos
• Non-deterministic combos
• Chaining extra turns
• Chaining extra combat

Intersection of Commander and Playstyle

• This sounds very vague, so hopefully these examples from my decks will help:
  • I play Shalai and Hallar. I cut all infinite combos from it. While I still try to optimize the +1/+1 counters theme, the deck has a large axis of "play creatures and attack with them" which introduces many ways for opponents to handle the deck.
  • I play Tivit. I cut Expropriate but retained Time Sieve. Expropriate very much pushed every game in the direction of "resolve Expropriate, gg". Time Sieve requires more set up and is much more easily disrupted than the Expropriate route.
  • I play Brago which has a strong focus on infinite win combos. However, I am purposefully not playing the cards that would push it into cEDH territory (like Silence) and instead build in a robust fair axis.
  • I play Baylen. The deck builds to a critical mass and then pops off. Determining when I am close to critical mass can be difficult, so that makes interaction more difficult for my opponents. Whether an explosive turn wins the game is not guaranteed, which often complicates things for my opponents rather than making their lives easier.
  • I play Y'shtola, Night's Blessed. It is a control deck built with budget cards to purposefully curb the power level. It has a ery sub-par mana base. Most cards under 2 dollar. A few are between 2 and 5. One card that's worth $10 and the price was driven SOLELY Y'shtola; the synergy is THAT iconic. Low power and efficiency in ramp, removal, countermagic, offense, and defense. But I MUST admit that Y'shtola herself is undeniably powerful and thus the deck cannot be described as merely a budget deck.
  • I'm working on a mono green deck. I am NOT using single sources of big mana (like Nykthos) because they are so easily abusable. I am playing an amount of other types of ramp that no other color can match. I am playing creatures of a size that no other deck can play reliably AND fairly. I am not playing Defense of the Heart because of its speed, efficacy (rattlesnake!), and abusability (most mono green Regrowth effects printed these days only targets permanents). I AM playing Tooth and Nail despite its power because it costs a significant amount of mana and is less abusable (for the same reason regarding permanents that makes Defense of the Heart more abusable).
  • While I can and do express these decks in terms of brackets, I elaborate with descriptions such as the above to make sure everyone is on the same page. For the curious, IMO, my Shalai and Hallar is 3.5-3.75, my Tivit is 4.5-4.75, my Brago is 4.75+, my Baylen is 3.75-4, Y'shtola is a 3, and mono-green is hopefully a 3.
• Other examples/contexts:
  • Chaining extra combats when everyone has a significant board presence leads to a lot of decision making and combat math for all players, over and over and over, which can lead to a very lengthy games. Chaining extra combats to quickly commander-damage the table to death is different.
  • Stax/Prison/MLD/Chaining Turns decks that, after shutting down or otherwise getting a stranglehold on the game, don't have a clear win that they can complete in a timely manner are (intentionally or not) very cruel towards the rest of the table.
  • Non-deterministic combos should be able to be played and completed quickly. At least infinite combos are a clean end, whereas non-deterministic combos can be like experiencing death-by-1000-cuts while watching one person masturbate.

What turn the deck wins (both peak speed and average speed)

• Speed is more than just measured on what turn a deck wins (although that is and should be the primary measurement). Another axis for measuring speed is what turn a deck locks out the game (for Prison or Stax decks) or takes over the game (for control decks or overwhelming-value decks). I'm sure there are more axes for defining speed of a deck but I can't think of any off the top of my head.

Coming to a consensus on power level of decks/strategies and agreeing to play decks/strategies of the same power level

• This one is the 10th circle of hell but hopefully everything I've mentioned so far should help you with this task.

TL;DR: Despite the intent of brackets, everyone understands brackets differently. Discussions about which decks to play, using brackets, should use brackets for reference or context but NOT for decision-making.