@Irres169Thanks for your answer.
The part about "Bronze 2 with 20 bomb badge only currently Bronze" is what I found not well thought in the SBMM.
Because there will be always a player who is "only currently Bronze".
At some performance level, with K/D ratio being the main factor in a battle royale, players should not be as low as Bronze.
Being a Bronze could be K/D <0.2 (by bins of 0.05)
Silver 0.2<=K/D<0.5 (by bins of 0.075)
Gold 0.5<=K/D<1 (by bins of 0.125)
Platinum 1<=K/D<1.5 (by bins of 0.125)
Diamond 1.5<=K/D<2 (by bins of 0.125)
Master 2<=K/D
I don't think I have a physical limitation (unless of sequels from a youth accident that I would not be aware of), I was a pretty good console player when young in fighting games and could pull some amazing feats of precision and coordination on a controler, but never had a PC and was pretty bad when playing FPSes on my friend's PC. And when I finally got my own, I was 25+, and had hard time getting good at CounterStrike.
Then I left games for like 12 years, so I'm "old",
having relatively bad reflexes (when on 3D aim trainer, on flicking I am at 0.3/0.8s in response time but always take 0.8-1 s to reach the target).
I don't want to use a controler because I would be pissed of about myself to have to use aim assist to be able to compete.
I got a little better by deliberately training on the range and 3D aim trainer (could do with Aim lab, it is just easier to play in browser for me at the moment) but still at global 0.07 K/D (started in Season 8) and at 0.12 on this season in BR/Arena (0.06 in ranked)
Apart of my aim, I think I have a pretty good sense of items and maps now (played like 300h, kind of grinded this), I support the team and share cells, batteries, sometimes giving a weapon to teammate if they get none on respawn, I try to raise/respawn and flank and so on, but I can't help and get lasered most of the time when it come to mid-close range fights.
I feel a lot that when with better players, I "play my best game" (indeed, I am getting carried and survive longer hence higher damage, but even if they are not ordering me around I get better positioning and so on).
So indeed, I have a problem with fighting movement (mine, not the others), and sometimes feel like I did perfect choices and some others when I mess big time and I don't know why, I just try and get lasered.
My sensitivity is average 🏈, no mouse accel, sensitivity 1 or so with ADS for all optics, I use ping when I don't have rangefinder to find out distance and snipe better to compensate distance.
But I guess my worst drawbacks are that I am too slow moving and aiming, only secondary that I don't always use the maps optimaly.