All brokers were able to do it, they just didn't because commissions were easy profit and there was no competition.
$0 commissions aren't a big deal either. If you just buy and hold, it makes no difference. If you trade actively then a real broker with better tech and order management is worth way more than the fees.
$0 commissions aren't a big deal either. If you just buy and hold, it makes no difference. If you trade actively then a real broker with better tech and order management is worth way more than the fees.