I thought MissTake's response was really good and covers pretty much everything

“Thanks to Apple”?

The original iPad was a 32 bit A8 single core CPU that topped out as 1Ghz and with 256MB Ram and used the ARMv7 instruction set.

How do you expect a modern day OS with requirements to deal with real world sensors, and user requirements that didn’t exist back then, to run against that?

The latest iPads have 2GB Ram, are 64 bit, run multiple cores and have embedded motion coprocessors and neural capabilities running a much later instruction set.

Let’s be reasonable here - that device is now about to be 14 years old.

And, if “the hardware works beautifully” how is it “pretty much a brick”?

iPads are not the same as laptops or desktops. Sure, you can still run some Linux distros on older 32 bit hardware, but everyone who does knows of the limitations of doing so and realize that they lack the horsepower of modern day computers and use them accordingly.