Hiding certain fields from contacts for users

My idea is:
Field-level permissions of contact data seen on Web UI meaning that fields that contain PII or other sensitive data could be hidden on the Web UI for the viewer. This could be also called “hiding” the data. The administrator would be able to mark certain fields as “hidden”. The data in database would remain unchanged. The data could be hidden from the user either by showing him [hidden] placeholder instead of real value. This means that some kind of additional “see hidden values” permission to contacts should be added. There’s also a problem with being able to “discover” certain PII using segment filters but for this there could be a permission allowing/disallowing using “hidden” fields in segments.
Creating contacts would be still possible, selected fields would just become “hidden” after contact creation.
Editing contacts would be also possible, hidden fields would not show a textbox, clicking to edit a field would clear it completely and show an empty textbox. Super simple example of what I mean by editing “hidden” fields:

I think these groups of people would benefit from this idea:
Companies that want to reduce access to personal data for their employees and enforce principle of least privilege.

Why I think they would benefit from this idea:
Instead of denying access to view contacts employees could still have access to contacts and some of their data, like custom fields etc. If the sole purpose for some employees would be to create segments based on non-PII data, creating and scheduling automated campaigns, creating emails and landing pages then there would be no need for them to access PII of contacts. One could think of stripping all PII from contacts before importing them to Mautic but there are certain PII like email which are needed for sending campaigns.

Any code or resources to support this idea:
Sadly no

Are you willing to work on this idea?:
Sadly also no, I have zero experience with PHP.

What skills and resources do you need to explore this further?