Yes, and that's why there are mining pools, where Joe Bloggs connects his computer to a pool of other similarly underpowered computers to perform the complex ca

Yes, and that's why there are mining pools, where Joe Bloggs connects his computer to a pool of other similarly underpowered computers to perform the complex calculations required to mine a block in a distributed fashion. Then when a block is mined, the pool owner acquires the 12.5 btc reward and distributes it to all the pool participants based on how much computation power/time each participant contributed to the overall pool, keeping a small bit for themselves for the overhead of managing the pool. Obviously you have to trust your pool operator. Also at this point in the BTC world, the difficulty has become so high that Joe Bloggs will never acquire any meaningful amount of BTC, even in a pool. There are specialized arrays of GPUs that can perform calculations at rates much higher than any standard PC or laptop. The same principles apply to any other bitcoin-like blockchain currency though.