[Bender]

Everyone used to query the root servers directly from their ISP or corporate edge servers until the big platforms wanted to gather more of everyone's data in the name of "keeping people safe" from "bad ISP's". As with any manipulation campaign there are a few incidents corporate propagandists can site to say, "See! We are protecting you!!" forcing people to debate the issue and knowing the majority will accept the default settings. Blocking all the DoH/DoT resolvers would be trivial for any ISP to do just as I have been doing at home since the inception of DoH.

The root Anycast clusters are absolutely designed to handle the entire internet querying them which I do from Unbound. If one wishes to help reduce load they can enable large memory caches and rewrite min-ttl to something sane to protect the root servers from Amazon EC2's default 5 second ttl and others like them. Blocking known spam and tracking domains also helps reduce the total number of queries. Groups of friends can even further reduce the load by setting up their own DoH/DoT servers using Unbound DNS and sharing the cache and using cron to keep their favorite domains hot in the cache and increasing private by making the crond queries from a VPS node.

Here's my cache stats for a 3 day uptime:

    total.num.cachehits=18149
    total.num.cachemiss=2300
    total.num.prefetch=4561

Memory usage permitting up to 1.5 GB:

     Private  +   Shared  =  RAM used Program
    343.1 MiB + 523.5 KiB = 343.6 MiB unbound