When we look for or value using a service, what we are looking for is comfort. Strive to the minimum to accomplish a task. To forget to do something while that something is done automatically. We live in a world where this is increasingly needed, since the amount of things we have to attend daily from our devices does not stop growing.
This, properly implemented, can be very advantageous. An example: Time Machine only asks you to connect a hard drive to start saving backup copies of your Mac and you can (almost) forget about that task. Other third-party services, which we use daily, do the same. But not everything is a path of roses. In fact, that "comfort" ends up causing significant long-term problems for the general user.
Bad news: you've probably neglected the space of your devices
Let's use more examples. WhatsApp and Telegram: send messages and don't worry. Google Photos: Upload photos and take care. iCloud: save everything you want in the cloud and take care of yourself. Gmail: Stop deleting emails, archive them and take care of yourself. Photos on Mac: put all your photos in the application and take care of yourself. In all of them there is a basic problem, and we cannot truly forget and gain that comfort that we are promised.
The reason is very simple: in all these services, storage represents an inevitable limit that all users have to face at some time or another. And if they follow that premise of comfort, it can be a problem that is not solved until after a few days.
Approximately three out of four of the users I speak with don't know that WhatsApp messages are taking up space on their iPhone
I see it myself in the training I do for general and professional users. A fact from my own experience: three out of four of those users don't even know that WhatsApp conversations take up space. And the primary problem of approximately 70% of those same customers, the reason they request training with me, is to solve storage problems. I have come to see WhatsApp instances occupying a whopping 51 GB on an iPhone.
Another case, and Apple itself, is that of iCloud Drive allowing you to store the Documents and Desktop folders of a Mac. It is something that is offered to the user during the first configuration wizard, and the vast majority of them activate it without knowing exactly what it is. And it's very easy for those folders to fill the 5 GB of free iCloud Drive storage in a matter of days.
The case of Mail vs Gmail
Another good way to differentiate the management approach of two services is to use Gmail versus Use an iCloud email If we have become accustomed to managing Gmail emails from your website, what we will surely do is archive all emails, regardless of whether we need to keep them or not. We save the dilemma to deal with the decision to eliminate it or not. As there is so much storage in Google accounts, we don't need to.
We only need to configure that Gmail account on a client such as Mail to see the consequences: although we choose to synchronize the most recent emails, thousands and thousands of messages are downloaded. And when the mail storage is full, then the problems will begin.
However, iCloud mail has the disadvantage of having only 5 GB of space, and it is also a space that must be shared along with many other things. Therefore, there is room for few messages. But if we give in to these conditions, we force ourselves to maintain a constant order of our emails. We make the decision to eliminate unnecessary emails the instant we receive and read them, we don't leave it for a "later" that never comes.
With this I don't want to say that the limited space of iCloud is a good thing, far from it, but I want to affirm that from that we draw a lesson: the best thing to maintain our long-term productivity is maintain an order that guarantees that we will not have storage problems after a while.
The solution: educate the user towards regular maintenance
Where I want to go is that every service has to educate the user, warning you that you have to keep that storage at bay. Inform you that you should regularly clean WhatsApp messages, photo libraries on iCloud and on the Mac or Gmail emails; however much storage space is offered in all those services.
Some services have applied good measures to solve this. For example, iMessage allows us to automatically delete all messages that have more than one month or a year of expiration. In this way, the storage that this message history occupies never exceeds an approximate amount of space. And if you want to be more specific, you can have audio messages automatically deleted after a month or only two minutes after sending or receiving and listening. Something like in WhatsApp or Telegram will save many problems for users.
We can also mention the tool to delete macOS files, which we can locate in the 'About this Mac' window and that helps us a lot to have a global view of what more storage occupies in the computer. The same can be said for iOS / iPadOS. It is a step, but seeing daily how general users fail to keep storage at bay, it is clear that more awareness about this is needed.
You can start right now with your own example: see how much storage your mail occupies. What all your WhatsApp messages occupy. Kneaded space in your Mac's photo library. A little discipline can save you a lot of long-term trouble.