Yes. There is the odd foreigner who does not have a VPN in China but almost all do.
If you do not have a VPN you cannot check Facebook, twitter, plus other social media, anything google will not work (including some website that use google plugins), some random sites wont work, Dropbox and a number of other downloading or uploading issues will happen.
Technically China does not accept VPNs to be used. That said, other than block them occasionally, they allow them to exist and be used.
It is important to get your VPN on your phone before going to China. Especially if you use Google Play (as that will not work).
Also many of the app stores read your location and when your in China there is a chance that the VPNs will not come up.
The best VPN keeps changing. In the past Express was the go to, and then Nord VPN.
Those are both paid VPN services. It costs roughly $10 per month.
There are Free VPNs but most people find them a lot less reliable.