Bitcoin can be adjusted at any time with a soft fork. They almost did it with Segwit2x but decided against it due to lack of community consensus. Anyway, bcash hasn't had a block larger than 0.21 MB in the last 50 blocks so I don't know who they are fooling thinking they need 8. I had to go back over 200 blocks to find one bigger than 1 MB. It's like a bad joke.

Anyway, with zero network strain their average fee per transaction for the last few blocks is over 20 cents. If I want to buy coffee I am not paying a 20 cent transaction fee. In the same number of blocks Bitcoin had 10X the number of transactions, despite having 1/8th the block size. Yes, Bitcoin cash would likely be 1/8th of the cost per tx but when Bitcoin is averaging $16 per tx at that rate that kind of improvement just isn't enough. You'd need gigabyte blocks before that math starts making sense and by then you'd have a tradeoff with speed.