Yes, although some can not, the vulnerability which
Checkra1n [1] exploits being an example of such. In this case I consider this to be a good thing since it makes it possible to circumvent vendor-imposed restrictions. I like to be the one who gets to decide what runs on my hardware, I see no need to hand off this responsibility to any vendor no matter how virtuous they portray themselves (or are portrayed as such by others).
I really don't understand the fawning over Apple Inc. when it comes to their claims of supporting privacy, I trust them no more nor less than I trust other similar companies. I know I can keep my devices ad-free because I am the one who decides what gets to run and what does not, which software gets network access and which does not, what goes through the firewall and what not. I also know what software gets access to which OS features and what does not. Can this veil of security be circumvented by a serious opponent? Sure, there are likely to be bugs in the software and holes in the veil, no more or less than there are such bugs and holes in other systems. I deem the chance of a serious opponent singling out me and my devices as slim so for now I assume I can use my devices without being mined by the ad-tech industry.
I don't get ads on any of them.
[1] https://cydia-app.com/checkrain/