But yes, anyone can invest through any method, can invest with any source of income. But it is better to invest by deciding which one will be good for his portfolio. Because if a person invests today and has to sell it after 2 days, it will never be good for him.
I believe your statement may confuse people who are new to investing. Yes, anyone who has the money can invest in Bitcoin, but it is not a good idea to invest with any money that comes your way. Every good investor has a plan, which means you set the amount you are willing to invest weekly or monthly and ensure that the money cannot be used for other important things like rent, food, or emergencies, if you invest without a plan, you may end up using money that was meant to be used for other needs, which can cause serious issues later.
Bitcoin is like any other investment, the price can fall and rise at any time, so you should only use extra money that you can afford to leave in the investment for a long time, even if the price falls. This is why planning is very important, you need to keep the money that can cover your other needs separate from your investing funds.