However, what I'm trying to get at is that, for example on iOS you still can't block in-app non-Safari ads at all. On Android you can do that if you want to, and a lot more, you can also block specific connections, block device-specific identifiers, APN lists, accelerometers, wake state, etc - it's a better compromise for someone concerned about privacy than other platforms even with this considered right now.
Can you still brick it? Yes. Is it likely if you type the two commands as you're told to on the website? No.
Also, bricking doesn't just happen, if you understand what you're doing you'll be fine. That "some risk" isn't random, it's in the case that you do something incredibly stupid. Get a custom recovery on there as soon as possible and you can pretty much recover anything.
Did you hear about SafetyNet? https://koz.io/inside-safetynet/
On Android devices with unlocked bootloaders, a great amount of apps won't work.
Android Pay, Snapchat, Pokémon Go, etc.
Google has tried to fight rooting as much as possible.
So, yes, they can do something: blow fuses in the fucking system.
From what I've seen the only mention of such fuses on Google devices is one that enables secure boot from factory and forces you to run the unlock command as I mentioned to reflash your bootloader - nothing to do with safetynet or anything similar.
Let me know if I'm missing a device which does actually do this. Yes, it's theoretically possible, but requires sufficient crypto hardware and protection to make it significant and it'd be a significant shift in direction for Google to go this route currently in my opinion.
Of course a full safetynet emulation that would spoof the check as a different device would also be an option... but it'd be a pretty big undertaking, but one which I'm sure would happen if this ever became a remotely significant threat.
One caveat here - Google devices are probably some of the most allowing of root access and full device ownership - easily unlocked bootloaders basically allow it to be a one button process.
Some manufacturers make you put your device on a shitlist with them before they'll give you a key to unlock the bootloader and root it - others, like Apple, won't allow you to at all.
Once you are rooted, you do have full ability to block everything and get fine-grained permission control via XPrivacy for example. Android devices are actually some of the best here mostly due to strong community support. You can't even get this control if you want it on many mobile devices these days.