Is "Yext business listing" a valid link building strategy?

Links from Yext Listings can help. They are a good start. 

14% of Yext listings are apps

8% of Yext listing websites forbid the Googlebot

30% of Yext listings websites that allow the Googlebot have nofollowed links

2% of followable links from Yext listing websites have redirects

In conclusion: 47% of Yext Listings could be valid links

Limitations

If Google can’t find it, the link can’t help you.

Only homepage links.

Easy links are not quality.