DC is a GOAT contender album. Pac had three classics in a row. But none of those albums, on their own, are GOAT contenders. Pac's biggest strength was that run, after dropping two lackluster albums and ramping up as an MC. People who were around at the time know Pac wasn't considered an elite rapper on some MC shyt. But he was ramping up.
Pac is the odd man out in this final four as he doesn't have a GOAT contender album compared to DC, Illmatic and Criminal Minded.
I would say this is your perspective/opinion (which is fine) but I wouldn't say this is the opinion as a whole. There's a few things to speak about....
First 2 lacklustre albums, I wouldn't say that at all, I think they were very solid albums, probably 4 mic albums with some all time classic songs. He had some amazing work on those albums and memorable songs, if someone were to break down the songs on the albums would see some really classic songs.
Pac is the most widely picked GOAT choice, I think we can agree that, a lot of people would pick 7DT, AEOM or Me Against A World as a GOAT album. All 3 are in contention for that title to me, would probably pick AEOM personally but love 7DT and that's really a possibility. Those are high level elite classics to me, infact honestly all 3 are better to me than the 3 albums you mentioned. When it comes to magazines and reviewers and shyt yes maybe not but the people pick Pac albums often. I've come across countless Hip Hop heads that pick a Pac album as the GOAT album, it's usually 1 of the 3 mentioned and occasionally Thug Life.
On to offline can be drastic differences sometime and Hip Hop is huge. I think Cube was respected but was he considered the elite rapper on some skill shyt? I don't think so, I think people like Rakim, Kane, Nas, KRS-One and others were looked at as more skilled MC's. I think Cube was an MC that was respected cause he could rap and then later his approach/politics but I don't think he was considered the man on that level, though was considered vicious with shyt like No Vaseline, King Of The Hill (1 of my personal favourites as the song is just HARD).
I don't really hear Cube mentioned much in GOAT contention discussions nor in greatest album discussions offline, heard Straight Out Of Compton get some mentions occasionally but not a Cube solo. Some of the albums I hear about as GOAT contenders (having a WIDE vast reach of opinions) are shyt like Illmatic, Only Built 4 Cuban Linx, AEOM, 7 Day Theory, Me Against The World, It Takes A Nation Of Millions, Paid In Full, Criminal Minded, Ready To Die, Life After Death, The Great Adventures Of Slick Rick, Midnight Marauders or Low End Theory, occasionally The Score, The Chronic, Doggystyle, Resurrection occasionally, I honestly hear The Infamous or Hell On Earth more than any Cube solo album, Reasonable Doubt occasionally.
That's what I hear from the people anyway. Don't get me wrong I now we get all kinds of choices but those are some which I hear most often. For instance if you ask people The Chronic vs a Cube solo I think offline Chronic wins comfortably.