The difference is switching costs and the viability of alternatives. Even open source models are only a few months behind the frontier labs, which is a long time in tech but practically no time at all in the eyes of a business consumer. At best, one of the frontier labs will survive and get to flex its hegemonic muscle. But billions and billions of dollars worth of investments still get wiped out in that scenario, which I would still qualify as the bubble popping. This would be doubly true if the winner winds up being Google or Microsoft.