[Bender]

It is probably quite a bit slower though needing to have roundtrips at each stage of the resolution

My experience does not align with this. My Unbound instances cache only what I am requesting and I have full control over that cache memory allocation, min-ttl, zero-ttl serving and re-fetching, cron jobs that look up my most common requests hourly, etc... I do not have to share memory with anyone outside of my home. Just about anything I request on a regular basis is in the micro-seconds always shows as 0 milliseconds in dig. I've run performance tests against Unbound and all the major DNS recursive providers and my setup always wins for anything I use more than a few times a month or more than a dozen times in a year.

For the cases where I am requesting a domain for the first time the delay is a tiny fraction of the overall page loading of the site as belorn mentioned. I keep query response logs and that also has the response time for every DNS server I have queried. I also use those query response logs to build a table of domains that I look up hourly NS and A records to build the infrastructure cache in addition to resource record cache.

Now where there would be latency is if I had to enable my local Unbound -> DoT over Tinc VPN -> rented server Unbound -> root servers. That would only occur if my ISP decided to block anyone talking to the root servers directly and my DoT setup would only be in place while my legal teams get ready to roast my ISP and I start putting up billboards. That would of course be a waste of time and money when I could just get the IP's of censored sites from a cron-job running on multiple VM's and shove them into my hosts file. This could even be a public contribution into a git repo and automated on everyone's machines.

[copula4]

There is life outside major population centers. I have pings in excess of 200 ms to many major websites; if every DNS lookup requires doing several queries with 100-300 ms of waiting for each one, the web becomes unusable. From reading HN, users from e.g. New Zealand run into similar issues.

[Bender]

I too am in a rural area, just not as rural as NZ. My setup would also be 0ms in NZ and AU for 98+% of my requests. The real impactful delays come from the excessive requests browsers have to make to bloated frameworks, excessive cookies and third party integrations, ads, videos and so on. uBlock can clean some of that up but not all of it.