You can sell the altcoins you own to buy bitcoin. For this reason, you don't need to have a lot of altcoins and just focus on bitcoin. If you still want to invest in altcoins, you can just choose the top altcoins so you can hope to make a profit.
But it is difficult to know which altcoins can provide benefits for you because with so many altcoins on the market, you need to do research one by one. That is why many people cannot make a profit by investing in altcoins.
But if you decide to invest a larger portion in bitcoin, you can hope to make a profit during the bull run later. So be careful if you want to invest in altcoins and do your research before you decide.