Why, instead of safely entering a BIOS setup, does the cell phone brick when installing the Custom ROM wrongly? Wouldn’t this protection be better for users? I mean, this could be done through ADB.
Also, do you think it’s possible that this way of doing things will come to the computer, with ARM hoping to gain a good share of the market and all?
Phones don’t brick with installing a ROM wrong just the same PCs don’t brick when you fail to install an OS correctly on it. It just doesn’t have a bootable OS on it.
Most phones have a download mode / fastboot which does exactly what you’re asking for. You can pretty much always reflash a valid OS with fastboot.
BIOS on PCs is used for compatibility because most hardware manufacturers want to be compatible with existing operating systems. ARM does support UEFI.
Phones just don’t have UEFI, because 99.999% of the time it will run only one operating system: the manufacturer’s flavor of Android. Skipping an UEFI makes it boot faster because it can load directly into the Linux kernel which will initialize the hardware and already knows the precise hardware it’s expecting to be present through its device tree. Chromebooks do that on x86 as well: they skip the firmware part and boot into Linux as early as possible, because it boots faster and it’s a ton of code you don’t need when you can just let Linux deal with it. Both are purpose built to run Linux, there’s no point wasting time with a whole firmware interface nobody should ever need. Fastboot is a perfectly fine low-level bootloader interface that lets you flash ROMs just fine.