In essence, the statistics presented indicate that a group of individuals assessed a sample of domains to determine how many were being utilized for their intended purpose versus how many were not. They then calculated the ratio between the two:
https://www.spamhaus.org/statistics/tlds/

The choice of selection made was not accurate. A more appropriate approach would have been to exclusively consider spammers from the .biz domain (which constitutes 4.3% of the total domains) in order to have a comprehensive representation. Additionally, it is important to note that the study included domain zones of varying sizes.

A more informative analysis would have been possible if the same number of domains were analyzed in each of these zones (as a percentage of the total domains within each zone).

The guys are certainly good, I mean the ones who did the calculations and stuff like that. However, it seems to me that they took a certain region (country or continent), at least I did not find any mention of this in their article. For example, in my experience, I do not trust .xyz, as well as .abc. I often find sites with these registers, and often they are owned by people and companies that offer fake services or risky high-yield offers.
I was surprised to find .top and .cf in the list.

I try to be open-minded, but everything I write is based on my experience and the experience of my colleagues. The worst domain zones are registered in the eastern part of Europe, Asia and Africa. I am now talking about: .st, .tk, .tc, .gs, .ws , .bg .cf .ga .gq .ml
In addition, the files that you will download from the .info zone in 1 out of 12 cases will crash your computer. A lot of spam comes from .ro sites, so I strongly do not recommend opening an online store. When you think about the price of a domain name, think about its value in the eyes of the Internet community.

The DomainTools report has identified a list of domain name zones that are considered to be the most dangerous. These include .buzz, .gq, .ga, .rest, and .ml for phishing; .buzz, .xyz, .cc, .cfd, and .cyou for malware; and .xyz, .cam, .bar, .surf, and .click for spam.

In general, it is observed that cheap domain zones are often utilized for illegal activities. This prevalence can be attributed to the fact that domain names can be blocked easily, prompting criminals to swiftly switch to a new domain. Consequently, domains with low costs are more likely to be purchased and used by fraudsters.