I don't think so! Unless you "accidently" boot into TWRP recovery and then "accidently" wipe the ENTIRE system partition! The chances of this happening is less than witnessing a Bigfoot in the wilderness, that ALSO happens to be taking a leak while whistling Mission Impossible theme.

On a more serious note, most manufacturers don't even offer unlocked bootloaders so there's literally NO WAY you can wipe the OS or brick the device for good.
Go with an iPhone 6S Plus if you really and I mean REALLY want an iDevice and just can't abide with Android.
They're pretty similar, despite the ENORMOUS difference in price tags. Take a look:
Don't waste your money on the iPhone 8 Plus. And if you MUST have to drop 100 grands on a phone, for whatever reason (I'm not judging!), then try to score either an iPhone XR or iPhone X.
Hope it helps.
EDIT:
After watching the aforementioned video, I came to SHOCKING realization that the iPhone 6S Plus is actually FASTER than the iPhone 8 Plus when it comes to everyday apps (Excluding games).
That's Apple for ya!