The point presented by the post is plain wrong, people were using non-ISP recursors for a long time already and this was not problem due to the fact that EDNS Client Subnet has been a thing for a while now.
The problem mentioned in the post is specific to Cloudflare, as they do not support EDNS Client Subnet anyway, even over plain UDP53
The problem mentioned in the post is specific to Cloudflare, as they do not support EDNS Client Subnet anyway, even over plain UDP53
more reading: https://www.samknows.com/blog/dns-over-https-performance