That is true.

However, I would say that the effect of this outage on customer retention will be (relatively) smaller than it would be for a smaller CDN.

Maybe? Maybe not? It depends on the nature of the outage and how motivated their customers are to switch over to a new service.

The good news is that we're just living in a perfect natural experiment:

Cloudflare just caused a massive internet outage costing millions of dollars worldwide, in part due to a very sloppy mistake that definitely ought to have been prevented (using Rust's “unwrap” in production ). Let's see how many customers they lose because of that and we'll see how big are their incentives. (If you look at the evolution of their share value, it doesn't look like the incident terrified their shareholders at least…)

That experiment already happened last year with Crowdstrike. Nothing detrimental happened. Their revenue actually increased and stock went up