It's not my opinion that once you enter bitcoin system you own nothing.
Wrong. You can't own Bitcoin and "nothing" at the same time. That's an oxymoron. Whether it's something in digital or some other form is irrelevant. Whether you see any value in it or not is irrelevant as well. You obviously own "something" so your argument is invalid.
And it's not my opinion that all systems where you own nothing by being member, collapse eventually.
Based on what facts? As I have said before, there was nothing like Bitcoin before it, and that is an undeniable fact, so you cannot arbitrarily compare it to anything that existed before.
The facts that the record of membership is currently digital, decentralized, traded on the market mean nothing. People eventually stop trading their ownership of something for a mere membership status.
That's your opinion, and I accept it even if I don't agree with it. So when do you think this will happen? In five years? In fifty years? In our lifetimes? In ten generations? When the human race becomes extinct? When the sun becomes a supernova??