Since January 2018, the number of uncle-blocks in the Ethereum blockchain (ETH) has decreased by 90% (from 2.000 to 250). This is mainly due to an increase in the efficiency of the distribution process of confirmed blocks and a decrease in the number of transactions.
Ancle-blocks are network blocks that did not become part of the longest blockchain. They produced in cases when two miners start working on calculating the same block, but one of them adds a block to the network quickly, so the block of the second miner becomes obsolete. For the addition of uncle-blocks, miners receive a reward, so getting outdated blocks is profitable. However, a large number of uncle-blocks leads to an artificial bloat of the blockchain.
The reduction in the number of obsolete units is facilitated by a decrease in the number of transactions: the average number of remittances per day fell almost 3 times – from 1.4 million to 400 thousands. However, despite the decrease in the number of uncle-blocks and transactions, Ethereum miners do not increase the daily gas limit, as this will increase the resource requirements for the operation of the network node, in particular, due to the increased gas limit, the data in the block will increase therefore, the blockchain will weigh much more.
The situation with mining Ethereum is aggravated by the intention of cryptocurrency developers to apply measures aimed at reducing the efficiency of mining ETH at ASIC miners. This project will be implemented as part of the hard fork of ProgPoW, which is scheduled for June 2019. Now programmers are testing a new algorithm for ProgPow and another hard fork of Metropolis Istanbul, scheduled for this fall.