Bitcoin was like a single entity before it was later separated into 2 separate block chains in 2017
Wrong.
Bitcoin is an open source protocol with an open source software all released under a license known as MIT that allows anyone to create a copy of it for themselves. Throughout the bitcoin history tens of thousands of people have created copies of bitcoin.
None of these mean bitcoin split in tens of thousands of chains just because they created a poor copy of it.
The hard fork between Bitcoin and Bitcoin cash was done in part to increase the processing limit from 1 megabyte to 8 megabytes
Wrong.
The scammers behind bcash created this poor copy so that they could make a lot of money from their scam. The reality is that the bcash average block size is in 100-300 kilobytes which is only 8% of the bitcoin blocks sizes.