I find it perplexing that so many (especially newbies) don't seem to be concerned about the pending Eth POS.  I believe the following to be facts but if anyone can rationally argue any of these points, I would be very interested to hear it.  It's quite possible I'm the stupid one but so far I haven't heard any reasonable rationale to counter the following logical chain.

1. Eth goes POS
2. Immediately, all the gpus currently mining Eth, switch to mining much smaller coins.
3. The enormous amount of hash power causes an enormous increase in difficulty for these smaller coins, resulting in:
4. Smaller coins mining profitability crashing through the floor, way below the electric cost for most miners.

At the moment, other coins are profitable.  Not as profitable as Eth but nonetheless still can generate more revenue than the electricity costs.  But consider a 100x increase in hash power that will result when erstwhile Eth miners switch over.  100 x hash power = 1/100 revenue per hash  (This is a very rough approximation).  Therefore if a card is currently earning $1 a day in revenue, it will drop to 1 cent a day.  Obviously no profit at all here.

Of course very quickly people will start turning off their rigs when they see they can no longer make money.  After a short period of time (weeks maybe), difficulty will drop and an equilibrium will be reached whereby the few miners with the lowest electric cost and the most efficient cards will be left mining with some degree of profitability.  But the majority of current miners will be out of the game.

This is not my opinion, it is factual.  Unless someone can fault my logic. (Please, please do!)

The Eth POS is not like a bear market.  It's a game changer for gpu mining.  There is no other POW coin that is anywhere near Eth's dominance.  The best you can hope for is that EIP1559 continues to be delayed because when it happens, it will be the end of gpu mining for most people.

Probably the worst time ever to be buying overpriced cards and starting mining.