I will add that if you consider investing in altcoins as short term then you should also not use money for daily needs or money that you cannot afford to lose investing. Since investing in altcoins is a hundred times riskier than bitcoin, they can even disappear suddenly and we will lose everything. Unlike bitcoin, if it drops suddenly it will also recover in the future. In short, whether it is a long-term or short-term investment, bitcoin or altcoin should only use idle money.
If we are determined to invest long term in bitcoin and will only sell when it hits ATH or $100k, buying for 25k or 27k won't make a big difference unless you invest hundreds thousand each time, IMO.
That's right, it will be more risky compared to bitcoin, as many happened in the past few years, many people lost their money suddenly because they trusted coins that were still unclear of their potential and maybe they came because they were carried away by the hype due to some significant news circulating. And also true as you say, it is very clear to emphasize that you should not use money that will be used or maybe you feel unacceptable to whatever happens to your money there including losses. Because it is very possible if in the end altcoins can disappear suddenly. Basically, in terms of investment everything has a risk including in bitcoin too, but there are some that have a risk that is not too significant and that will be able to make you calmer when knowing various good news related to its potential and also with the history of movements during the price, and that may be enough to convince us that we are still in a safe position by knowing the clarity of bitcoin itself for example. So basically allocate your money to a place that you trust with various clarity that is there, and use money that you don't mind if it's lost, and still use your main plan to hold it longer for a bigger profit in the future.