How much you will benefit from the better connection varies depending on your own access and where you live. Valve's data suggests that 43 of the players will see at least some reduction in teams, while 10 percent will see their ping times fall by 40 ms or more. The biggest improvements tend to be in parts of Europe and India, where large clumps of people will see the difference.
This is not a strict altruistic gesture on the valve part. The more studios depend on their network, the less incentive they need to make their catalog accessible through rival services such as the Epic Game Store. Likewise, players who have a choice of stores may be more likely to choose Steam if they think they will have a better experience. This can still prove beneficial if you enjoy multiplayer games – just because it's not very positive.