I don't buy the "ping-pong" theory, in which a counterspell gets counterspelled, which also gets counterspelled by another mage, which then gets counterspelled by yet another mage, etc. That's a lot of third-level spell slots and reactions getting eaten up in a single round of combat. I'm sure it technically could happen, but I've never seen it in practice. I doubt very many people actually have.
At the end of the day, you have to decide that the juice is worth the squeeze. Is your Fireball so vital and important that the entire outcome of combat hinges on it? So much so that your party is willing to spend twice the usual number of spell slots so that you can both cast it and counterspell an incoming counterspell? Probably not.
But if it really is that important, your first thought should be "what if that guy in the sparkly robes over there can cast Counterspell?" Maybe don't lead with your superpowered Win-Button spell at the top of Round 1. Maybe hide first, or drink a potion of invisibility, or move out of counterspell range, cast it with a higher-level spell slot, trick Mr. SparklyRobes into wasting his reaction, etc., beforehand. Maybe do any one of a half-dozen things to ensure that the spell you are about to cast, which is tactically vital to the success of the mission, has the best chance to succeed.
I file this under Not Broken/Don't Fix.