Why do apps now require subscriptions, causing financial strain and emotional distress for users?

Developers of the apps can decide if and how they may want compensation for writing and supporting an app. Some apps are truly 100% free. Some have in-app purchase or subscriptions which offer extra features. Some apps may have trial subscriptions and after the trial is over you will have to pay to use the app. Apple does not control this, the developers do. If you wish to, you can provide feedback to a developer by clicking here.

If a big media distributor is involved they have to pay the content developers (e.g., musicians, actors, etc.). Few are the kind to distribute items for free. You may have been using a free trial to let you test the content but that trial has now ended and you will have to pay to see the content. If you do not want to do that then I can recommend your local public library which has a lot of content at no direct cost to you. Some even have streaming content.

Requirements for subscriptions are up to the developers of said apps.

Developers are real people and need to make a living off of their apps so subscriptions for added features are a way to do that. They can't devote hours upon hours of their time to developing and maintaining an App and not get any income off of it. It's simply not a sustainable model. It takes, time, resources and money to develop and maintain apps.

If they have locked some previously free features behind a subscription now, you would need to talk to the app developer about that. Apple has no control over what the app developers do with their apps as long as they abide by the App Store regulations and terms.

click here ➜ How to contact an App Developer - Apple Support

I doubt Disney apps and other games with Marsha and the Bear have just now started to do this. Probably and more likely is you or your granddaughter had not noticed they had certain features behind subscriptions until now when you tried to use them.

Apps require in-app purchases and subscriptions because the developers have found that that they can get away with these pricing models.

Many years ago, it was common for smartphone and tablet apps to cost a small amount of money up front - but then to have no ongoing charges afterwards. Many casual game developers even provided existing customers with new levels for free. Now, it seems as if most developers prefer to offer “free” apps that are like arcade games stocked with functionality locked away behind subscriptions, or artificial consumables, that cost real money. Instead of paying once, you pay and pay and pay.

You can probably “thank” Adobe for the current popularity of subscriptions (rental). They were one of the first - if not the first - high-profile vendors to switch their main desktop applications to subscription (rental) only.

P.S. - The Apple Arcade subscription service offers access to a number of games that do not have additional in-app purchase or subscription fees. I don’t know if the games it offers are of interest to you - but if they are, that’s one way to avoid getting nickel and dimed by a zillion separate subscriptions and in-app purchases.