

I wholeheartedly disagree, DNS needs servers running, which can go down or their configuration break, this makes it less reliable for certain use cases where reliability is of the essence.
For example, I’m a maintainer of a server virtualization platform, where communication between hosts is done using IP only because DNS is simply not reliable enough, this means having to use IPs as subjects.














You might want to take a look at https://github.com/olivierlambert/calrs
it was made as a reaction to cal.com not meeting the needs of the creator, like being selfhood table and being caldav compatible.
Note that I cannot vouch for it since I have not used it.