Some SEOs are wary of using these non-Latin characters in URLs because
of the way it might display in certain browsers, or in certain text
cases when the link is copied and pasted somewhere online. While
having spammy-looking links is never a good thing, I personally think
the possible benefit in search results is worth the drawback.
For example, the Japanese Wikipedia page for soccer (サッカー) might
display as
<http://ja.wikipedia.org/wiki/%E3%82%B5%E3%83%83%E3%82%AB%E3%83%BC>
or as <http://ja.wikipedia.org/wiki/サッカー>
, depending on the browser
you use.
While some SEOs will be afraid of the potential for your URLs to look
spammy with strings of numbers letters and percent signs, the benefit
of having the non-Latin characters show up bolded in the URL of your
search snippet is worth that, especially when most browsers are
displaying the original characters anyway.
Source.