> This isn't remotely true.

Nothing in your comment rejects or disproves the claim that egress costs are vendor lockdown.

Your link to the bandwidth alliance explicitly states that their justification for network costs is unloading infrastructure costs onto end users as data fees. That's their only and best justification. This is clearly a business decision that has no bearing in operational costs.

Some cloud providers charge nothing, others only start charging after hitting a high threshold from a single instance. Do they not operate infrastructure?

It's their business, it's their business model. Some restaurants charge you for a glass of tap water too. Let's not pretend they do it because of infrastructure costs.