My company was paying $20 a month. We were heavily depended on CF, we'd have been happy to pay more.
But... the one feature we wanted was for our accounts team to have their own login so the ops team didn't have to download invoices every month. Nope, that one feature required an enterprise plan which they quoted $4,000 a month for.
Companies where you have to log in and download invoices are the worst. If there's a viable alternative to their products I switch immediately. You make it seem like it's not a big deal, but a reasonably sized startup has dozens of service providers. Should we pay every little service $4k/mo just to save the communications and context switching overhead?
You jest, but imagine how time consuming it would be if every app we used was setup like CloudFlare, where only the one super admin can deal with billing.
Also in these days of remote work, it's a problem if the credit card details need updating - either you have to give the company card details over a slack call, or you need to give a card holder your root password.
Imagine already paying for a service and then having someone snark at you for wanting things for free.
I tried to exercise some restraint this time, but screw it. Here's another rant:
Beware of Cloudflare's tactic of luring people in to their CDN product with "free" bandwidth, and then locking useful features arbitrarily behind what I can only imagine is a thousands of dollars per month enterprise plan. Just look at their cache-purging page for a super obvious example of this (there are plenty more, way too many to list), everything other than basic purge by URL is enterprise only: https://developers.cloudflare.com/cache/how-to/purge-cache/
These days Cloudflare is literally my last choice for a CDN for my new projects. My new go-to is bunny.net, who charges a reasonable usage-based fee for bandwidth and gives you unfettered access to all the features they've built (and doesn't route your users to farther/closer nodes based on how much you pay: https://cloudflare-test.judge.sh/). Though I'd even reach for Cloudfront with their expensive bandwidth costs these days, because at least their pricing is transparent and scales smoothly with usage, and they don't arbitrarily cut you off from useful features that you might not know you need yet.
Even their bandwidth might not really be "free", since I've heard if you actually use any significant amount, the sales people will come knocking on your door to coerce you to get on the same enterprise plan or have your site taken down.
Can I ask out of interest (most of my projects are high perf/low traffic) what kind of traffic you are dealing with at the point you decide you need a CDN?
I don't really use a CDN to manage high traffic volumes. It's more to provide a better, lower-latency experience for my users regardless of where they access my apps from.