Ponder this… Tracer is THE highest skill cap hero in the game. You need to play her extremely well to get decent value.
Mechanics have to be top notch as does the engagement timing, your initiation angles and recall routes. Those are base necessary. Then you need to be managing your blinks and recalls at all times or you will feed and die.
Its easier to get value with any other DPS because they are all more forgiving; if you make a mistake with tracer you get punished, its that simple.
PS. I just realized you had a video linked and so watched it. That is not how you play a tracer.
You engaged before the team fight had properly started.
You chose to go on the junkrat at close range? junk jumps and you track his feet doing almost no DMG to him.
He then gets a mercy pocket AND is also stood in a 76 heal pad at the same time and you STILL attempt to shoot him? forcing you to recall.
You’re now at full HP and waste your blinks going for a heal pad when you’re full HP?
You then choose to engage a 76 who is with a mercy.
The mercy has less than full HP yet you choose to engage the 76 who can easily rocket/melee combo burst you but doesn’t need to as he has a mercy pocket.
You die…obviously.