I haven't encountered that yet, but I'm starting to encounter mobile apps as required proof of membership for things. My family got a membership to a children's museum a few weeks ago, and the expectation is that my wife and I have their app on our phones to get inside. For our second visit, I brought our printed receipt, but my wife had to stand there downloading and installing their app so that we could use our guest passes. The person at the front desk didn't seem to have any other way to do it. Similarly, my neighborhood's community pool and fitness center requires the Brivo Mobile Pass app to get through the front door (and it's unattended, so there's nobody who can just look you up in the system and let you in).
I think the worst part of this is businesses that do this all have different crappy apps. My gym has their own app that must be scanned upon entry. But their app is often slow and unresponsive, and unpredictably logs out. Often at the entry, a person will be stuck trying to reload the app, possibly hindered by their phone having switched to the gym's questionable wifi. Multiple other people will be stuck behind them, having preemptively loaded the app and QR code while walking to the door.
This replaced keychain fobs with a barcode, which had none of these annoyances.
On Android you should be able to create new user accounts on the phone which are completely separated and can be quickly switched between. I used to create one with just WhatsApp installed for instance.
Alternatively if you are rooted Xprivacy[0] does what you asked, allowing you to grant apps permissions but then feeding them fake data as configured.
No idea about iOS though.
EDIT: There seems to be an app called Insular[1] which also works like Xprivacy, but doesn't require root at all and comes with a couple of extra features like the ability to have multiple instances of an app installed. Haven't tried this one though and I have no idea if it even runs on newer versions of Android.
As someone that does not own a phone I have had to explain I cannot install apps many times. Normally when I bring up the word discrimination, they always find a backup path they do not advertise.
I do not own a cell phone and have attended many Ticketmaster events in recent years. If you explain you do not have a compatible device, and sometimes use the word discrimination, they will take a credit card by phone and have paper tickets waiting for you at the box office. It annoys them, but not my problem. Prepaid credit cards are recommended for privacy.
I have not installed the TM app - you can add a ticket to Apple Wallet from the website, and every order I've seen has "don't have a phone? go to the box office for tickets when you arrive" somewhere
They're not allowing that in general any longer. I wasn't allowed to log in to their site this summer without phone text verification.
However, I believe they still have a ticket printer for emergencies, such as when you show up at the window saying you broke your phone, but just happened to print a receipt before leaving.