No matter how much people buy, they can't buy >100% of the shares on the market unless GameStop issues new shares. The people buying are betting that when these hedge funds need to cover, they will be covering ~120% of the number of shares (the amount of shorted stock) on the market. That covers everyone that has shares right now.
So right now, its a tug of war (hence the volatility). Its a zero sum game where one side will definitely lose. You can argue that the company isn't worth anything and that buyers will get hurt, but only when <100% of the stock is shorted.
edit (below):
The loser will be the one holding 100% of the stock. At that point the stock would plummet because all the buyers have left. Meaning if the hedge fund loses, they are not just covering at a higher price (and thus continuing to drive it up even more), they will effectively be buying worthless stock.
I consider this a battle of trading strategies. The fundamental value of the company is beside the point. Hedge funds have done this to each other before, that's why there's an existing term for it - short squeeze. Its definitely covered in a textbook for first year business school students.