You can take your phone to anyone you like and have them make whatever changes you pay for.

That is currently your right.

It’s not clear what your complaint is.

Whom can I pay for to install something like Termux on my iPad? Apple not only forbids third-parties from offering such a service via the App Store, they also do their best to prevent this by any other path. That they are not 100% successful (jailbreaks) doesn't mean the situation is anyhow comparable to cars, where there is a wide ecosystem of 3rd party support for customization.

There are engineers who can do it for you if you are willing to pay.

If you want easier customization buy Android. That is one of the selling points.

Not all cars are engineered to be cheap to customize easily.

You are detracting from the point. The point isn't that there is exactly one alternative, which is somewhat more customizable, the point is that Apple makes it willfully difficult to customize. This is not equal to cars.

Apple doesn’t make it willfully different to customize.

They make it willfully difficult to compromise it.

It’s not equal to cars, because cars aren’t software and are not vulnerable to the many attacks that phones are.

It seems like you want a more customizable device and are happy to accept the risks.

Why buy an iPhone if it isn’t what you want?

No they make it willfully difficult to customize. Installing applications is not compromising. And stop with strawmen like "Why buy an iPhone if it isn’t what you want? ". The discussion is about the freedom any buyer of any product should have. Fundamental customer rights.

Customers do have the freedom you claim.

Installing Apps can definitely be compromising: https://en.m.wikipedia.org/wiki/Trojan_horse_(computing)

Perhaps you should brush up on computer security.

Just because it’s hard to modify an incredibly complex piece of microelectronics and a huge software base doesn’t mean you don’t have the right.

What you are asking for has nothing to do with freedom.

It has to do with you wanting to force Apple to design their product differently to support your individual desires.

I’m correct to point out that for someone like you, a choice is already available.

My car displays speed in kph and has no option to display it in mph. How do I get that changed?