You're right, we're still on the same point here. The point is, invest in an amount you can afford to lose, no matter what it is. Not to belittle bitcoin for being skeptical, but simply to control your real-world finances to have a more organized life. Moreover, Bitcoin itself has proven for decades that it is the best instrument in supporting financial freedom and avoiding inflation that occurs in FIAT.
Investing an amount you can afford to lose is the right advice to give, but at the same time, I don't think there is any amount anyone is willing to lose that will not affect them.
That being said, if one can protect their holdings very well, I will say they should invest what they can stay without for a long period of time and not just what they can afford to lose. As you have highlighted in your last line of comment, holding fiat is risky of being affected by inflation.