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??
Well, you can use semantic tricks but that means nothing. Holding a record and owning something are two entirely different things. When you buy a stock you hold a record of name and quality, but you own capital or equity. When you buy bitcoin you hold a record of name and number but own nothing. If I would write down my name and "1,000,000 ounces of gold" next to it, I would hold a record of name and number, but I would own nothing. You can write down whatever record you want. Either you or Satoshi. You can put that record on digital or paper media. But you would still own nothing. By buying bitcoin you gave up your ownership of something and become member of bitcoin community. Membership in this community identified via numbers. Even if you buy all the membership identifications, you would still own nothing. You would simply be the holder of a number "18,000,000". And you're not even able to eat this. That is how this membership is worthless. Having all the bitcoins in the world, but not even being able to eat.