MacBook pro 15 inch 2019 screen flickers with purple horizontal lines when iPhone is near my MacBook screen
This sounds like the MacBook's hardware is very much more susceptible to RF interference than it ought to be. You should never see artefacts such as those. It might be that there is a build fault (e.g. accidental omission of some shielding component), or some other hardware fault that is causing the unusual sensitivity issues.

You should take the computer to an Apple authorised service centre where you can demonstrate the issue for assessment and repair options.