That's simply not true. Electricity prices vary by a considerable factor, even among the cheapest sources. The Bitcoin price is identical, globally. These two can only coexist if there is a considerable margin to be made in mining, allowing for it to be profitable in a relatively wide span of electricity prices (of course still excluding the highest-priced sources, it is not that wide!).
As far as my information goes, there were times when mining a >30k$ coin was possible for less than 4k$ in electricity, if you had access to really cheap sources. That's far from "don't really make much money".
There might not exist a single global market, but whenever the Bitcoin price is different in these markets, there's an arbitrage opportunity. As a silly example, if the Bitcoin price was 4.000 USD in one market and 40.000 USD in another market, you could buy one Bitcoin in the first one, sell it in the second one, and pocket the 36.000 USD difference. Buying Bitcoin in a market increases the price there (suppose there were 10 Bitcoin for 4.000 USD each and 12 Bitcoin for 4.200 USD each, after the first 10 Bitcoin are bought the price is now 4.200 USD), and selling Bitcoin in a market decreases the price there (it's the same dynamic in the opposite direction). After some time, the prices will converge.
That is: as long as arbitrage between the markets is viable (for instance, it must be possible to move Bitcoin and fiat between the markets at a low enough cost), even though there's no single global market, the prices will tend to be close enough.
Bitcoin price is identical globally. The price of bitcoin in USD/GBP/EUR is pretty much the same with respect to the values of each currency. There may be outliers, eg. Venezuela, but that's because it might be priced in the local currency, which is itself inflating at a rapid pace, so it loses value against bitcoin and the dollar or euro
Can "Bitcoin price" be defined as something other than what it's selling for on various exchanges? Right now BTC is going for $31,599 on Bitpanda, $31,384 on eToro, and $30,327 on Coinmama.
As far as my information goes, there were times when mining a >30k$ coin was possible for less than 4k$ in electricity, if you had access to really cheap sources. That's far from "don't really make much money".