They don't have the venture capital to burn at start... It all begins with dumping. First prices and intro offers are unsustainable... You can not start competing when other side started by burning massive piles of money.
Right, but investors were happy to fund those intro offers with the hope that they'll be rewarded in the end with market share. In fact they were funding multiple competing companies (eg. uber eats, doordash, grubhub). If the Asian competitors are fundamentally cheaper than their Western counterparts, then it'd be a non-brainer investors to invest in them instead, because over the long term they'll have a cost advantage.