Not really. There are two outcomes that are more likely to happen than others, both of which are terrible for consumers.

In one scenario, Amazon utterly destroys the ability of others to sustain their business, and then raises their own prices dramatically: a fairly typical monopoly scenario.

In another there are two tiers: Amazon and everyone else, which is only marginally better.

In both cases competition is reduced and the consumer suffers.

> then raises their own prices dramatically

When has that happened? How many times? And how much did it offset the previous period of low prices for consumers?

Instead of criticising Amazon for being able to achieve next-day delivery why don't you criticise FedEx for not being able to achieve it? We want to select out badly run inefficient businesses, not support them artificially. If there's a monopoly developing it's because everyone else is incompetent. Tackle them!