I agree with you at some point because bitcoin price is going higher, we tend to compare historical values and if we see the price much higher then current price would seem cheap. Maybe it's good time to buy some cheap altcoins and when the price of bitcoin stabilizes they will start moving up too (of course if the projects are legit and promising), like some people invested in LINK when the price was very cheap.
If you already know the characteristics of a new project or new coin then you can reconsider not investing in it. but if you are confident in a project that you may have researched before then invest some of the money you have. see Bitcoin is starting to move significantly, why not take part in BTC?
investing in bitcoin for this is very risky because the price is too high, don't let you buy bitcoin at a high price, it's better to buy other altcoins, because the price I see has shown a decrease due to bitcoin has increased, and for new projects there is nothing wrong with investing , but should always be on the lookout