A "Free Updated" mod is almost never actually updated. While Microsoft releases security patches every month, the modder releases a new version every 6–12 months. During that window, your device remains vulnerable to known exploits that have already been fixed in the official version.
The desire to avoid paying $70/year is valid, especially for students and light users. The good news? You do not need a because Microsoft already offers a robust free tier. microsoft office mod apk premium unlocked free updated
If you need Microsoft Office for free, here are legitimate alternatives: A "Free Updated" mod is almost never actually updated