I think my pointing out that the terminology IP and and domain names are not completely interchangeable triggered some kind of unnecessary avalanche of replies that don’t really improve the discussion that the OP started, that was not my intent.
An IP addresses is just a number (the bit count doesn’t matter for this example), an A record in DNS (domain name) is a human understandable string of text that is “mapped” to that address. So by using IP or domain you reach the same destination (in most cases). So usability-wise they are the same (ignoring the fact that one has to do an extra DNS request)
127.0.0.1 is an IP address in human-readable form (dotted-decimal notation).
2130706433 is the same IP address in decimal form without grouping.
locahost is a hostname that typically points to the address 127.0.0.1
pinging any one of the these 3 all produces the exact same result. So yes functionally they are nearly the same.
My original reply was to clarify what the OP stated merely to improve readability and accuracy regarding the terms used related to the networking world.
One thing that would improve the graph in my opinion, unless there is an IPv6 slice in the pie chart, I find stating IPv4 unnecessary when just saying IP would suffice. Also domain (DNS) can point to both IPv4 (A record) and IPv6 (AAAA record), so by specifically saying “IPv4” vs domain, the word “domain” in this context could mean any number of things
However it is clear that OP meant the difference of servers advertising using dotted-decimal notation vs fully qualified domain names. Side note, I’m still interested in seeing if finding out how many of the domain based servers are also using SRV records, although since you can’t just scrape that from the listings and would require doing actual DNS requests it would seem like more work than it’s worth.