I cannot connect to (specifically) google.com with any app using cellular data All other websites work and can be quickly accessed, even youtube.com will load. google.com will simply not load at all when I try to connect to it over cellular data. It does work over Wi-Fi, however. I tried using a different browser, the Google app, restarting the iPhone, everything. Funny thing though, the Google feed loads in the Google app, yet I cannot search with google within the app.
This sounds like it may be an issue with your mobile service provider's DNS. I would try to Reset Network Settings to see if that clears out the cached DNS results.

To reset network settings:
Tap SettingsGeneral > Reset > Reset Network Settings