I think the no counters idea is a little weird. It’s not that Tracer doesn’t have any counters aside from Brig and the builders, she just has the most 50/50 matchups in the game that rely on player skill for the counter to win. At least for me personally that’s what I loved the most about her from perspective, she felt fair to play.
A good Cassidy can just either flash you when you get too close or just two-tap headshot you if you try to poke in higher ranks. Plus in OW2 he gets increased survivability from his combat roll so he can get of 12 high damage shots if a Tracer gets too aggro after recall.
A Sombra can deny you value after a hack in both games. In OW1 Sombra’s health pool and translocating ability just either outlasts you and kills you or she can TP out, in which case only Sombra is getting value out of the duel from denying you access to the backline.
A better Genji will kill a better Tracer a high percentage of the time in my experience. This is more of a skill based matchup as I was talking about. Who wins is determined by skill and advantages each player has in a given situation.
Reaper doesn’t have as much of a skill ceiling as Tracer, nor does he have a neutral game, but in an enclosed space Reaper can shine with his burst damage and tankiness. His forgiving passive and his wraith allow him to get peel freely with you unable to do anything about it.
You can try poking out a Mei but she’s a general counter against flankers. Getting behind her to burst her down works too if she’s unaware, but 1) she’ll generally have peel if she’s in the middle of a team and 2) a good Mei can two-tap headshot you with her secondary fire, so poke battles are inherently riskier. Reaper is the better choice her than Tracer up close.
The Ana matchup is tipped more towards Tracer, but Ana can still Anti-nade and you force out your recall if she can’t hit the sleep. A well positioned Ana will get peel, it’s just than in OW2 they can outheal your burst instead of relying on cooldowns like Bap immortal field.
You shouldn’t really be dueling tanks at all if you’re low as Tracer. Her best matchup is against Winston and Rein since they have no way to deal with you, but anyone else takes too much time to kill in a straight duel for you to get value.
Obviously hitscans can punish sloppy rotations and rollouts when outside of her effective range. Tracer’s entire win condition relies on her getting into effective range and getting the most value out of her recall.
Brig and the builders are just instant swaps for me if we’re talking about pub games. An annoying Moira is also just dumb to duel so I swap to characters that have an easier time in these specific situations. It’s almost like Tracer can’t be effective if used in the wrong engagement ranges or against the wrong characters.