My understanding is... There is a scaling problem. It could be help by increasing the block size (like segwit2x) But the miners don't want to fix it because they like the high transaction fees.
A global currency controlled by a few warehouses in china sure does sound optimal.
I thought the big miners were the ones pushing for increasing block sizes b/c it would create an even higher barrier to entry to successfully mine a block that would allow the big miners to get bigger and consolidate power...
As others have pointed out, your understanding is backwards. Mining is heavily centralised already (in China of all places!), and larger block sizes would only exacerbate the mining centralisation, which is probably why the biggest fans of larger blocks are the Chinese miners.
You have it flipped. Recall that most miners (by hash rate) supported segwit2x. Miners want bigger blocks because they can make more through volume.