At the current difficulty rate, it can take a solo miner almost five years to mine a single bitcoin. That is the average rate for miners, even for those using the most efficient mining hardware. Bitcoin mining remains one of the most popular cryptocurrency ventures for profit-seekers, along with Ethereum mining. Thousands of miners continue to buy mining equipment and use large amounts of electricity to mine bitcoin, which has drawn criticism for its environmental impact.
Only one megabyte of transaction data can fit into a single bitcoin block. The 1 MB limit was set by Satoshi Nakamoto, and this has become a matter of controversy, as some miners believe that the block size should be increased to accommodate more data, which would effectively mean that the bitcoin network could process and verify transactions more quickly. For example, with five or ten ASICs you could mine 0.01 BTC a day and in 100 days you would have mined a full Bitcoin. Of course, the time it takes to mine a Bitcoin will depend on several factors.