It’s not normal that at certain BRs, especially around 12.0, a player ends up with 95% of battles being uptiers, while at BRs around 9.3 to 10.7 - 11, they mostly get downtiers. A more balanced system would make sense — something like a 3/3/3 ratio: 3 full uptiers, 3 downtiers, and 3 partial uptiers. I highly doubt players would mind waiting an extra 10–20 seconds for a match if it meant a better gameplay experience. I still remember a few years ago when players had no problem waiting around a minute or so for a battle, sometimes even longer.
From Gaijin’s economic perspective, of course it makes sense to aim for faster battle rotations, which leads to quicker spending of in-game currency. But there should be a limit to this approach, and I believe that limit has been significantly crossed in recent months.
Widening the BR spread would also help — and hopefully that will happen eventually — but as has become a fine Gaijin tradition, it will likely be too little, too late.