Supports are generally better than everyone else, and dictate the meta.
Zenyatta counters tanks, just the concept. You have a really tanky team? Slap a discord on em.
Lucio counters bunkers. You need to speed boost to break through.
Ana counters healing heavy comps, etc.
Moira and brig still counter flankers. The peel is unreal.
Baptiste… is obvious. Doesnt need to be said. Immortality dummy good
The best swaps to counter a comp are usually the supports and tanks, they just cover the most bases. Utility will always be more powerful to counter than raw killing strength, and supports usually equip the whole team with tools to disable the counter; zen discord, lucio speed, brig/moira peel, mercy rez, ana nades + sleep.