I don't want to compare between bitcoin and altcoin because it is different. It is right that altcoin follows bitcoin movements, and if bitcoin now increases to the $13k, the altcoin will follow to increase. But maybe the altcoin increases will need a long time to grow and back to the last price.
The altcoin can give you a big profit, especially for the altcoin that has a good market position. Altcoin such as ethereum, bnb, and the other coin will take it's time to rise again, but if bitcoin price drops again, the altcoin will not have a chance to increase, but it will drop too.
Investing in bitcoin and altcoin will have the same risk, but I think you can select investing in bitcoin and use bitcoin for your main investment for the long term. The altcoin will be used for your secondary investment that will work in the short term. But that will be up to you because we have different strategies to make a profit.
you tried to explain that Bitcoin is a rather lower risk investment than altcoins, and that is probably the fact, but one should bear in mind that there are different altcoins, and take longer period to draw conclusions
at the moment, Bitcoin is in the best position to grow, since there is a tone of positive news, but if you look at six month chart, most altcoins provided better return compared to Bitcoin, at the moment part of that profit is going back to Bitcoin, and will be back to altcoins after some time and Bitcoin rise in the meantime
of course, one should draw his own conclusions, and do research before investment, this is not a financial advise in any mean