It is possible, but absurd. Why more layers if layer 1 works fine just increasing the maximum block size? Bitcoin Cash did it and works flawlessly. Just try it.
> Bitcoin cash pays the price through centralisation
What centralization? If you are referring to the node implementations, it has several [0]: Bitcoin Node, Bitcoin Unlimited, Bitcoin Verde,... Bitcoin BTC has basically one: Bitcoin Core [1]. If you mean mining, it's the same as BTC, same mining algorithm, same miners.
> It can still only manage 100 transactions/second
True for now, but it's way more than it needs right now now [2]. But don't worry, this month upgrades to ABLA [3], and will be able to scale to as many tx/s as needed.
https://bitcoin.stackexchange.com/questions/67158/what-are-c...