Steam game libraries routinely become worth hundreds or thousands of dollars as you spend more money to acquire digital goods. You can't move those to a different account, sell the entire account safely, or activate the titles you already own on a new platform. Nobody would spend all that money on repurchasing all their games just because the EA launcher is more shiny.

The lock-in cost is real and literal. It's far easier to migrate to a different voice comms system (which is free, usually), since you only have to convince your existing social network to create an account on the new thing.