Thanks for posting. We see you're unable to locate the NFC Tag Reader option in the Control Center on your iPhone. We're happy to share some information about this.
Because your iPhone 11 Pro Max supports NFC tag reading automatically, you wouldn't see the toggle option like you do on some other devices, like the iPhone 7 you mentioned. This link has a little more info: iOS 14 - Features - Apple. The text below is in reference to NFC in iOS 14:
"Supported automatically on iPhone XS, iPhone XS Max, iPhone XR, iPhone 11, iPhone 11 Pro, and iPhone 11 Pro Max. Supported after turning on NFC scan mode from Control Center on iPhone 7, iPhone 7 Plus, iPhone 8, iPhone 8 Plus, and iPhone X."
We hope this answers your question!