"If both sides are Proto and are trying their absolute hardest with their absolute best gear, then how can it be a stomp?"

Your argument is basically "Well, close fights require us to die a lot so we are just going to use Prototype gear so we don't die a lot because we don't make enough money to die a lot" despite the fact that if you were using a Basic suit and died 10 times you would likely spend less money than on 2 deaths with Proto gear. Even more so, going back to the original quote, if both sides have the same logic then you are going to naturally get close games using your logic that the reason it is a stomp is because of Prototype gear.

Or, put simply, "We are using the most expensive gear in the game so we can save money. Increase the money we earn in game and we won't use the most expensive gear in the game. Honest."

The reason it is often a stomp is because matchmaking doesn't properly work in regards to squads. When it is myself solo against several squads when we have none, the enemy could be running all standard gear and the Blueberries and I running prototype or advanced and it wouldn't matter. Them working together, setting up proper defenses, and supporting each other is what would win the game. It doesn't exactly help the situation when people tend to use their most expensive fits when it squads because they are less likely to lose them.