The dynamics of mining make this impossible. If Bitcoin were worth millions, then miners could spend millions on electricity to find each block and still make a profit. And because they're competing with hashrate, they would do exactly that.
If you do the math, you'll find that basically all electricity would go to mining.
Before we would get to that point, the electricity price would start going up of course. For everybody. And guess what governments will do when the population starts rioting because they can't afford electricity? They'll ban all proof-of-work coins. Maybe all crypto just to be on the safe side.
If the max amount of Bitcoin is 21mio and we assume that a huge chunk of the economy will be payable with these Bitcoin. Then on Bitcoin has to be worth (at least) 1/21mio of that economy chunk.
That is one way to estimate a maximum possible value.
My point is that by assuming "Bitcoin cannot consume more than X % of all electricity or there will be trouble", you can calculate another maximum value which turns out to be much lower.
In fact, if you assume Bitcoin can consume no more than 1% of all electricity (before regulatory trouble starts brewing) and electricity costs 0.05 USD/kWh, then you get a maximum price which is pretty close to the current price.
If you do the math, you'll find that basically all electricity would go to mining.
Before we would get to that point, the electricity price would start going up of course. For everybody. And guess what governments will do when the population starts rioting because they can't afford electricity? They'll ban all proof-of-work coins. Maybe all crypto just to be on the safe side.