WOFF (and its successor WOFF2) are compressed file formats created specifically for web fonts. Although regular OpenType fonts (TTF and OTF files) can be used as web fonts, such usage is not recommended as it usually contravenes license agreements—and the files are significantly larger.
So yeah, it would save on bandwidth and such on loading times.
https://fonts.google.com/knowledge/glossary/web_font
So yeah, it would save on bandwidth and such on loading times.