All of these stats are somewhat meaningless without common definitions. Number of users is not the same as active users.
If we compare similarweb’s estimates visits it’s 10.6 million for Gab and 7 billion for Twitter. Maybe it’s just my personal definition but these site were set up as direct competitors to Twitter and getting 0.1% of your main competitor’s traffic is definitely “very few people”.
Gettr gets 7m visits per month according to similarweb.
"Very few people" is a bit of an understatement...