So, all the miners race to mine the block but only the winner gets the 12.5 btc reward? Does that mean if you're a Joe Bloggs Bitcoin enthusiast, you'll never be able to get any reward if you only ever mine on your low key laptop setup?
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.
There's unfortunately some things that make it a bit of a race - network latency and block verification time. That's why there's so much work spent on shrinking these (the FIBRE network, libsecp256k1)
If you want to mine Bitcoins, you need a bunch of advantages. Special hardware, cheap space, low electricity cost, bulk manufacturing deals. Otherwise you probably aren't going to be breaking even, let alone profiting.