of course, all responsibility for the choice of the project and profit or loss of money lies entirely with the investor,and he should only blame himself
I agree! And in order not to blame yourself, you need not just throwing money away to the wind buying tokens of incomprehensible PPI, but rather reading and diving as much as possible into the project.
This is the basis-to study the project in detail, to communicate with the team before investing money. Risks are everywhere, but they can always be reduced!