Bitcoin Cash (BCH) forked from the Bitcoin (BTC) blockchain in August 2017, amid a heated block size debate. At the time the Bitcoin network was undergoing congestion due to increased transaction frequency and transaction fees began to exceed $1, going as high as $3 in June 2017.
The Bitcoin Cash community thought that increasing Bitcoin’s block size limit was the best method to increase scalability. Initially, when Bitcoin Cash was created, it had a block size limit of 8 MB, and this was later increased to 32 MB. But Bitcoin Cash (BCH) has a very low rate of adoption, and block sizes currently average less than 100 KB, making the block size increase above Bitcoin’s (BTC) 1 MB totally pointless, defeating the purpose of Bitcoin Cash (BCH).
The block explorer shows how Bitcoin Cash (BCH) cannot even reach 1 MB block sizes, let alone 32 MB. Block sizes of less than 10 KB are common, and there is an occasional block less than 1 KB. Blocks in excess of 100 KB are rare, and there are no blocks today anywhere near 1 MB. Therefore, Bitcoin Cash (BCH) could have a block size of 1 MB and function perfectly. The long term block size chart shows that block sizes have averaged well below 100 KB throughout December 2018.
There are a few instances in 2018 when Bitcoin Cash (BCH) exceeded 1 MB block sizes. In early September average block size briefly hit 1-3 MB, but this was from a “stress test” to prove transaction fees do not increase from increased transactions on the network.
In November, Bitcoin Cash (BCH) split into Bitcoin Cash ABC (now named Bitcoin Cash) and Bitcoin SV. The war between these Bitcoin Cash forks caused spam attacks that increased block sizes to 1-2 MB on average.
On Jan. 15 the average Bitcoin Cash (BCH) block size approached 5 mb, coinciding with the price of Bitcoin Cash (BCH) crashing from $2,700 to $1,500. This is perhaps the 1 case where Bitcoin Cash’s network legitimately had block sizes over 1 Mb, but it was due to people dumping their Bitcoin Cash (BCH) as fast as possible in a panic selling situation.
In summary, since Bitcoin Cash (BCH) has relatively low network activity when compared to Bitcoin (BTC), it seems that there was no point in creating Bitcoin Cash (BCH), since its block sizes are almost always below 100 KB.
Bitcoin (BTC) seems to have resolved its transaction fee problems with Segregated Witness (SegWit), which increases the block size to 1.2 MB on average. This is done by redefining the block size in terms of 1,000 units instead of 1,000 KB, and separating the witness data (signature data) from the Merkle Tree and counting each KB of the witness data as ¼ of a unit.
Also, the Bitcoin Lightning Network is maturing and can handle as much transaction volume as Bitcoin needs without increasing on-chain transactions or block size. In November 2018, the Lightning Network rapidly grew in capacity due to increasing Bitcoin transaction volume and proved that it is a solution which can completely mitigate rises in Bitcoin transaction fees. The fact that Bitcoin (BTC) has become scalable to increased transaction frequency makes the creation of Bitcoin Cash (BCH) even more pointless.