Why are .com, .net, and .org more popular than other domains?

Simply put, They were some of the first domain extensions created for general use. These TLD’s were introduced back in 1985 and have had a head start in regards to familiarity and establishment in the minds of most people. Many of the new TLD’s (.xyz, .club, .online and so on) first came out around 2012–2013.

So think about it, from the time that .net, .com and .org were introduced and other viable options became available was a difference of 28 years. And the phenomena of using underutilized country codes such as .co .me .tv and .io was not popularized until about 2010.

That is roughly 25 to 28 years of those extensions being the main/go to options as far as registering a domain name for general or commercial use, especially the .com. As time passed and availability of domain names in the ,com became limited, people naturally gravitated towards .net and .org.