I think, too much projectiles could make game crash and a lot of “hits” on players who even doesn’t know where they got shot. Like old Hanzo Scatter arrow. It’s fun if you think about, but not fun for the people who dies from them. 2 Orisa just ricocheting their attacks on walls and shields, also sigmas who actualy can do some sort of it. Could generate a “projectile zone” who could make stand by between those orisas really bad.
2 barriers are fine(maybe a little less regen - add 10% less regen or so - on that and a bit more cooldown - add 1 sec - on orisa barriers), we have a lot barrier breakers faster than the cooldown/regen of most of them. If you concentrate the fire on the right way. Even if not, you can use Reaper, junk, genji, tracer, sombra (the way they supposed to be). Also tanks like roadhog, wreckingball and winston to generate some disruption. Supports like zen, mercy and baptiste who can add more damage output to your team. Overwatch has a lot of characters and most of the time some player only pick like “10 of them”. The game have a lot good barrier breakers and a lot fun characters to play.
Overwatch without these aspects will turn in something very boring and very quickly. Barriers are good, but not that strong. Most of the time if you really just shot at it they will break very fast, but most of the time nobody does that. Or just one player does that. Zen concentrated fire, hanzo storm arrow, roadhog hits, symmetra beam, junk grenades, mccree flashbang, bastion, torb, zarya, pharah, echo all of them can deal just fine against barriers.
In this post I said like 15 of the heroes who can help or deal fine against barriers or even ignoring them. And most of the time barriers doesn’t even keep up too long, the only one who can keep a bit more it’s rein and he can’t do much stuff at long range. The others most of the time their barrier it’s up like 1-2 secs(at best), rein could be 1-4 secs, if they got good blows on their barrier. Like the time of the most of characters have until they die by most of the attacks. So if you have a barrier you have less damage troughput on your side at long range(sigma it’s a exception), and because of that you need stay close of your barrier tanks if you not, they will die and do nothing to the enemy team.