Currently well a built team comp NEEDS a composition of certain things to attack and defend effectively. These elements can change based on map choice or how a competitive team want to approach each half.

People ignore how agents with scouting abilities like sova, skye, ryze are basically also mandatory picks. You could nerf sova in any number of ways but he'd still be an 100% pick on certain maps because his util is necessary to play to round out in any consistent way. Same goes for viper, they have become staples in their own right.

The dash is a MANDATORY tool currently, in the same way that sentinel is mandatory to hold a difficult site or a flasher is needed scale up difficult areas you don't currently control. It allows an operator user to be so much more threatening, It allows space to be created in the most problematic chokes of a map, it gives your team the "pick" power it needs to find entry kills and open the round up.

No other duelist is effective enough in this way, Raze has double satchels, but they function in a much more gimmicky way that makes it a lot easier for her to die midair, yoru has a slow and predictable TP with an incredibly long recovery animation and activation, pheonix has literally nothing.

To me it seems likely that you could remove all of jett's abilities completely right down to leaving her with a single updraft, dash and smoke with no ultimate, and she'd still be picked competitively because of how team's need her and her dash for explosive executes and genuinely threatening defenses on maps with important points of contact to fight like ascent or icebox.

If you think jett is overpowered in casual low ranked play. You're probably just crying that you got shat on by a smurf, most jetts don't use her effectively, her soloq teams don't use the space she creates effectively, by the time she has enough money to get an operator your team was already getting smashed and tbh most pro's don't even use her ultimate effectively let alone a random plat 3. The only reason she might seem oppressive is because she allows a better player to beat you harder. But you're much much more likely to get stomped by a player with equal skill who uses, skye, sova, astra or any of these essential characters with extremely powerful util effectively. Killjoy was straight passively carrying games with the power her ultimate on attack and defensive setups bring to soloq games since her release basically up until her recent turret nerf.

Before you ask, no I don't play jett unless noone on my team is confident enough to lock her. I think we just need more agents present in the game that offer the same consistency in the areas of strength that make her a mandatory pick in competitive play.