Neither are the original bitcoin. They're block structures are both different. 1MB vs 1MB + SegWit vs 8MB
Or you could say they're both the original Bitcoin - as they both started in 2009 technically.
But I guess BCH is closest to Satoshi's white paper
The original bitcoin had no blocksize limit. Not until version 3
I think there is no problem at all with blockchain size increase.
If you can't come up with a better solution do increase blockchain size, until you can create a better solution.
It's much better than a giant pile of shit like SegWit2x