AWS's lock-in is in the egress. If you already got multiple petabytes ingested into AWS (for free), it's going to cost you a lot to send them to CF once.
Except you can put R2 in front of S3 and set it to "slurp" mode. That way as objects are requested through the normal course of use they'll be stored in R2. You can then keep S3 as a backup, or delete the objects that have moved over.
Being a proxy is cool.
The power dynamic is same as in retail whoever is closest to the
"edge" wins in the long term. Kindah glad I have a bunch of NET :)