I agree Kendrick is on an impressive run. The thing that most impresses me is that both albums are completely different. A lot of people would still be calling Kendrick an amazing artist/rapper/etc if he simply gave us GKMC 2. Instead he took a major risk and dismissed nearly every modern rap convention (trap, bangers, 808s, contemporary features, list of the hottest producers, etc). And the album is fantastic.
BTW I'm not a Drake fan but I think that guy's point was weak. You can make a monumental, classic, amazing album without it being socially conscious. If Drake made the rap version of Thriller would anyone refuse to call it classic because it was just love songs n shyt lol? Nah. Likewise TPAB isn't fantastic because of its social content. I've listened to so much average backpack shyt that I know being conscious doesn't mean you make great music.
I'll post some other thoughts later but one more for now: TPAB isn't classic. I don't call anything classic a year after release, or 6 months, or a day. GKMC is clearly classic for various reasons, from reviving the west coast on the mainstream level to being a near perfect rap album. Let's wait and live with TPAB before calling it classic. It's a fantastic album.