The mining power doesn't matter in that case, as the network adjusts to whatever mining power is there.
The limitation is in the protocol, or rather, its current implementation with the 1MB blocksize limit. It was originally implemented to make growth a little more predictable in the beginning, nothing else. Satoshi himself said that it's only to prevent spam, which was at a time before growth, when it wasn't obvious yet how well the self regulation with TX fees works.
After Satoshi disappeared, other people took over the development, and disagreements over how to continue began. What was mostly a technical argument at one point, became a political argument after Blockstream formed, which had taken investments from banks and had most of the core developers under them.
These then not only pushed for other means of scaling than just removing the blocksize cap, but also actively pushed against that, which split the community in half.
Now we have people who (very simplified) just want the blocksize cap increased, and others who support the scaling methods of Blockstream, namely segwit and, down the road, lightning.
This endless debate with both parts of the community calling the other's solution unsafe is what is currently crippling Bitcoins potential.