The only way you will come close to making mining worthwhile is if you can control the full-stack. From cutting edge R&D to manufacturing of the hardware as well as the supporting infrastructure. You must make a profit at every step. The old model of buying public available hardware, paying for power generation and renting space is out. If you do this then you wiil almost be on an equal footing to your competitors. To match the competition and have a small chanced of beating them you also need to control the underlying blockchain that your targeting. Such as the mining pool's and even have a stake in the blockchain project.    This is what I mean with controlling full-stack.