That's an issue with the fonts used by your system/browser. It's taken a few decades to reach the point where Unicode is becoming fairly universal. It might take another decade or two for fonts to catch up.
> Can someone tell me what purpose this serves
Letting humans enter and read text on computers. Letting devs write code in their native tongue.
> other than providing new and creative ways to obfuscate malicious Perl scripts (as if that wasn't already easy enough)
That's important too. Someone needs to figure out best practices for avoiding the problems that are inevitably going to come. And they are inevitable; many newer languages support Unicode in source code.
> Why do I need 91 different ways to type the number two?
Are you suggesting programming languages stick to just the world's most popular numeral systems? That would cut it down to 30:
But why stop there? What's so magical about having 30 instead of 91?
I mean, I assume you're not seriously suggesting there be only one way, English or the highway, to the rest of the world?
Substituting ᱁𑛂೩᮴୫᱆᥍𑇘᱙꘠ for 1234567890, though: that would definitely be considered malicious. Even if it does work in Perl 6.