Countless companies and industries enjoy making up scary stories when it comes to justifying their opposition to making it easier to repair your own tech. Apple claims that empowering consumers and bolstering independent repair shops will turn states into “hacker meccas.” The car industry insists that making it easier and cheaper to repair modern cars will be a boon to sexual predators.
That assumes that the manufacturers want to bring down prices. If they all keep using proprietary batteries they can use that as an excuse to keep prices high without looking greedy.