In theory you make 1 model of chip.
You manufacture them.
You test them. What clock speeds are they stable at. Are any of the cores faulty.
Many (probably most) will have defects. Some of them will be duds and must be thrown
The bits with the defects are switched off and resold as lower end hardware.
The common less powerful failure cases cost less and the rare more powerful successes cost more.
The high end stuff sells for more than the cost of manufacturing and the low end stuff goes for less. They offset each other.
So when people force a model of GPU to preform higher they are basically ignoring the Q.C. and are going to be dealing with undefined behaviour. Did the card get reduced just because it produced more heat at the higher levels (in which case a highend heatsint might counteract the issue) or because there is a core that returns faulty data.
That's only the theory though.
In reality it might be artificially screwed with to increase profits. Maybe there are many more successes than the desired price level matches. Maybe they are selling more cheaper stuff so they turn off the bits of the chips even though they passed the QC. There are only 2 companies selling gaming GPUs so there could be an artificial duopoly. Nvidia only have to be price competitive with AMD.
But I thought pro chips actually tended to be clocked a bit lower than gaming chips. There's no 'ignoring QC' there if you trick the board, quite the opposite.
Yes, the pro gpus have different clocks, ECC memory and there may be other differences in the board as well.