Aside from Bitcoin, ETH and BNB that concept of your is true, there's no assurance that old project will bounce back to it's last ATH but if you are willing to gamble and take that big risk, who knows fate brings you luck and the market will favor you with those old or new assets that you choose, again, there's a big risk when investing to this type of volatile market, the only thing that will allow to grow is your own experienced with the current market.
Maybe that's the point? Having btc, eth, bnb and busd on your wallet means that you have 4 things which you know that will be great in the future, well not so much BUSD because dollar loses value but thats mainly for being ready for any crash so that you could DCA if that happens.
Do you really need to buy into any other "big" name one? Like sol, ada, matic, avax, and whatever else? Should you? Should you invest into something that is even lower? Who cares about these? There is really no reason for people to invest into tiny cap stuff. I'd say just invest into the four I named, and just keep it that way, stake them if you can, and have a very long term hold, like over a decade, even two if you can.
I don't have any objections with your statement though for some investors they are still aiming to support those other projects aside from the main four assets that you wanted to hold, it's a case to case basis and all are depending to how you deal with your own research, if you established good relation with the developers of any project that you believe that will come up with good outcome aside from the four mentioned established cryptos.
Always do your own research and decide according to how you understand the concepts and the usages of the projects that you will use for your investment, the outcome will depend to how you patiently wait and if the analysis is correct to the value that you set for your selling position.