If many people wanted to buy another PoW coin instead of Bitcoin, the price of Bitcoin would rise, meaning it would generate more profit, which would make people buy only Bitcoin. Therefore, it is not possible for people to buy another
proof of work coin instead of Bitcoin because this would make Bitcoin's price increase generating more profit, which would prevent competition.
How so? I don't understand what you mean, if people buy other cryptocurrencies instead of Bitcoin, that wouldn't make the price of Bitcoin rise up or grow because the whole concept revolves around the demand and supply mechanism where the price of an asset only increases if the demand is high and supply is low, but if there is no much demand, the price wouldn't get affected even if the supply is low. So I don't see any reason why the price of Bitcoin would go up if people buy other PoW coins.
Please explain this a bit more.
In a normal company, competition forces companies to lower prices. In Bitcoin, the logic is inverse, it raises the price and prevents competition from emerging, which makes proof of work impossible to copy.
Cryptocurrencies are not like companies because their prices are not controlled by a central authority but their price depends on how much demand they have. Bitcoin has such a high value only because it is the most demanded cryptocurrency and it has a limited supply, another cryptocurrency can compete with it if it gets the same level of demand and has a low supply like it.