I understand all of that. I am currently running hyper drive installed through safestrap but it still feels governed apposed to a Google rom. We are still stuck on 4.3 and everywhere else has a later version. I still don't understand why you can't completely erase the internals to reload with a different loadout. Isn't it the same phone regardless of where you get it rather it be samsung or verizon or google?whenever we download updates it installs new cameras and radios I'm not talking about reverting I'm talking about completely shipping the phone down to nothing but download mode and install new kernels drivers and software. Just like the developers at any of the companies do except we won't have to do any testing or development
Then you have a brick which runs just the downloader. OK, it's not quite dead, because you can flash stuff. But what can you flash?
OK, so you want to "install new kernels drivers and software". That's not always possible. You flash kernels and and software using the bootloader, but the bootloader won't allow you to flash a kernel that's not pre-approved by Samsung. If you're rooted, the rest of the phone storage can be overwritten with whatever custom software you want, but there's a hitch. You can install whatever software you want EXCEPT for the kernel. (If not rooted, you can't even do that without a custom recovery, which the bootloader won't allow.)
The software that you flash depends on the kernel to drive the hardware, so you can't flash base software that requires services that the stock kernel doesn't provide. This is why only certain ROMs are available for Safestrap - you can't flash CyanogenMod on a Safestrapped i545 because CM isn't compatible with the Touchwiz kernel. It's theoretically possible to modify CM to make it work with a TW kernel, but nobody has done that (unsurprising, as it would be a lot of work that would have to be repeated each CM release.)
The bootloader chain is the way Samsung enforces the restrictions on what you can and can't do with your phone. With a locked bootloader (like ours), you're very limited. Until the bootloader protections are breached, what you propose can't be done.