If you want to be online, but want to block internet to certain apps like work apps, messaging apps etc, and continue using rest of your apps, you can do it using this app.
And no,this is not an ad. https://play.google.com/store/apps/details?id=dev.tuantv.android.netblocker
Yes. Honestly I wish more VPNs were having this as a built-in feature.