Why can't the newer generation women stand up to their MILs?

Most women of the current generation are working and are independent before marriage so why do we still let the whole saas bahu drama thing happen even now? Why can't you make it clear to your MILs that you can walk out any time so they don't have any power to bulldoze you? Is it years of social conditioning that holds us back from reclaiming our true independence?