Can someone explain to me, for what kinda of new projects would they use Perl/Raku in 2019 at all?
Not only that, but when Perl 5 was at the end of its life, comparing its libraries to both Python and Ruby, you'd often find the best library was for Perl.
Raku should be far faster than Python and Ruby and may in the future have better libraries with excellent concurrency support, making it a good choice to do processing over the data, not just converting it to the format you need. It has an easy interface with C and C++, so you can import libraries from there too, if you need more speed.
Before Python came to fame Perl was primarily used by two groups: 1) sys admins who needed bash style 1 liners, but in a cleaner language (This is where the dirty code stereotype comes from.) and 2) Web devs. Much of the early pre PHP internet and even post PHP internet was written in Perl. When Perl on hiatus the web world turned into this mess of frameworks like it is today. It used to be a more unified world.
And then there is the rare 3rd group. I worked on earlier ML projects in Perl before Python was a thing. I enjoyed Perl more than Python and so did the people around me. Moving to Python / R was somewhat painful knowing it could have been better. I hope Raku takes up this torch and is good as it appears to be.