Protecting from what? For 17 years Apple has dictated on over a billion users that they can only install apps that Apple approves. That's not protecting, that's gatekeeping, and it is just criminal considering no other major Mobile or Desktop OS does that.
Is the walled garden approach that Apple take, and millions of customers choose them for, kept secret from buyers somehow? I'm going to take a wild guess that they all know exactly what they are buying into, and the limitations and benefits of that platform. Don't like it, buy something else. Why is that so hard these days for people to comprehend. If enough people don't like it and take that approach then the company lose revenue and either go busty or change their direction to suit the majority.
As it happens however, the majority seem to like the devices and software they buy and accept some limitations as either a benefit to them (security for instance) or find them minor enough not to be a deal breaker.
Why do people these days feel the constant "everyone should bend to my will" mentality. Just go out and buy something else you do like, instead of demanding that a product already on the market, that no one is forcing you to buy, changes to suit you. It's an extension of the "me, me, me" attitude that is prevalent these days - millions and millions of other people in fact like what they are buying - if they didn't then they wouldn't buy or wouldn't be repeat customers, and Apple would lose $billions. Vote with your feet if you don't like it instead of trying to force your idea of what it should be on everyone else. Better still, go and design your own device and operating system and run it how you want and see how many customers you get - I wish you well in your endeavours - but leave everyone else to use their free will to do as they see fit.
It’s your device should always be your choice what you install on it
It certainly is, no argument from most people. However... you know when buying an Apple device that there are some restrictions on what you can download and install, and many people accept that limitation, and indeed welcome it as a benefit of the platform.
Don't like it, buy something else and stop complaining. No one is forcing anyone to buy into the Apple ecosystem or indeed to stay in it.
Apple has crippled iPadOS and consumers need the EU to force Apple to make moves that actually benefits the consumer. The fact that the real Chrome browser is not allowed on the iPad means the iPad as a web browsing machine is literally worse than a cheap Chromebook. Most developers put the majority of their effort to optimising their apps for the web and the best extensions are made for Chrome on desktop.
Safari is just a piece of junk. The only reason it has any marketshare at all on iOS and iPadOS is because Apple is being anticompetitive and doesn't have to compete with Google. When they do have to compete on MacOS, guess what. People are voting and the vast majority like and chose to install Chrome. Apple users claim Chrome users don't know any better and Safari is so much better but that's the argument Android and Windows users like to make about Apple users in general so that argument is moot.
The argument about which browser is best has been going on for as long as browsers have been around. It's largely down to personal preference. I use Safari extensively, but for some tasks find Firefox better. And also occasionally use Chrome for some things (usually a site which renders terribly on the others).
I buy Apple devices and know they come with Safari. I am freely able to download other browsers if I wish.
Apple designed the platform and we as consumers can choose to buy into it or not. I do so willingly, and if I wanted a browser that didn't exist on it, and it was a deal breaker, then I'd take my money elsewhere, as would most people.
But people still buy in the millions, and accept a number of limitations (or benefits as many see them).