I actually forgot to consider this angle, as the discussion was centred at archive.is. I'd imagine 1.1.1.1 has a very negative consequences for Netflix local caches, for example. This is where your local homegrown provider gets to save significant $$$$ due to interconnect/bandwidth costs by hosting a local Netflix cache through their appliance, and you get to benefit by the latest shows being locally cached, delivered at maximum speeds, instead of being hailed through the whole internet each time for each device.
If you're using 1.1.1.1, you're basically not only making sure that your internet will be much slower due to suboptimal CDN performance by any CDN other than Cloudflare CDN, but that you're also going to needlessly be running extra simultaneous streams of your favourite shows instead of fetching a local copy from your own ISP, increasing the cost of bandwidth transit to your ISP.
And, remember, you don't actually get any extra privacy by bypassing ECS in the first place, because your exact full IP address will have to be used to establish any subsequent TCP or UDP connections to make those requests for actual content in any case. You're basically breaking the whole internet by using 1.1.1.1, all for no real benefit! It's worse than we initially thought!
Is it possible for Netflix to use anycast?
For their appliances they can advertise to an ISP's routers via (i/e)BGP or OSPF / IS-IS to keep traffic internal, but have a fallback of having a presence in various IXPs.
Isn't this how Cloudflare works, anycast?