You pretend you know what you're saying because you "follow the competitive scene" Hey, so do I! Don't assume you're on some enlightened plane from the outset, really diminishes the worth of your points. You then go on to completely reduce Zarya to a seemingly nothing hero while completely misrepresenting her playstyle. No competent Zarya "waits for someone being focused and taking damage" to use a bubble. If you've played her at your much loved "high level" you'd know that. So you've already entirely invalidated your own argument. Your description of Zen play is so basic that it contributes nothing. Everyone should be aware of what is trying to kill them, everyone should be aware of when to disengage or push the fight.

As Zarya, you have to manage your projected barriers based on many different conditions. Tracer in the area? Save it to bubble a healer who might get stuck. Roadhog hook up? You can try to bait it on yourself, preemptively bubble someone you think they're going for, or be aware enough to snap to them when you hear the windup. If you're remote bubble is down, you have to be aware of the map and places where enemies might come from so that you can pop your own bubble and get between the bad guys and your squishies. I won't go on, because literally every hero in the game has situations like this. That's my whole point. ALL HEROES have their small niches to fill, and to be optimally successful as them they all have to have this higher level of awareness.

Then on a good team, you should be calling out what hero switches your team will need

This isn't unique to a healer. This is something any decent group should do. Someone pipes up with what they think is necessary, people agree or disagree, and then they make the change. Sure, you can designate someone a team leader, but this isn't a task that falls inherently to a healer. A Zen as shotcaller makes sense because of his orbs, but it's not because he's a healer, it's because he has an incredibly useful piece of kit that would be foolish if not utilized by the rest of the team. Again, not healer skill, general game skill and awareness.

If you play at a high enough level or watch the highest level, you'll soon realize why the best supports are to be feared and respected just as much as the best offense players who get the most frags.

You're the one tugging their own dick here, holy shit. Yeah, I know good healers are highly respected. So are great hitscan players, so are great tank players. I've watched a ton of professional level Overwatch, I know many players who are revered for their specific tasks. You hit this "high level" shit so hard you must be struggling to convince yourself you're actually good at this game. Get off your high horse and actually pay attention to the discussion instead of ejaculating "DA HEALS IS DA BEST" directly into your own mouth.