XDA Developers has been the authority since long before smartphones, lol, but welcome to the club!
No device is ever "impossible" to root. No lockout or tamperproofing is ever "impossible" to circumvent or neutralize. No encryption method is ever "impossible" to break.
It does take some time to decipher all the JTAG boundaries and spoof opcodes, to bypass lockout or DRM circuitry on the mainboard, to successfully interface embedded SMD logic/storage chips with external debugger/programmer hardwares, or to just crunch and brute all the hard number permutations on a bunch of computers. In absolute worst-case situations, the software can be extracted (and duplicated, then modified) by methodically exposing and examining the nano-scale circuit lithography under extreme magnification. (Note that expert hackers can exploit all the same approaches and tools that are used by teardown engineers and by forensic data recovery experts.)
And many consumer devices simply aren't popular, capable, or interesting enough to motivate such time-consuming efforts.
Fortunately for us, there's always serious hacker prestige attached to the first person(s) able to thoroughly pwn a new device, especially whenever an "evil faceless profit-grubbing corporation" throws down the gauntlet by proudly boasting their new DRM technology (whatever it is) is somehow "completely secure and ultimately, utterly unbreakable".
