As I have said before[1], I think the biggest thing slowed Perl adoption was the changing background of new developers. New folks just didn't have a background in shell, C, awk, and sed. This fact took Perl syntax from being amazingly intuitive and easy to adopt and turned it into obscure nonsense. As a newb what the heck are you going to think about constructs like the file test operators[2]?
[1] https://news.ycombinator.com/item?id=44726347#44752240
[2] https://perldoc.perl.org/functions/-X