It's not new. History is full of these schemes. Eventually everyone who wants bitcoin has bought it, and there are no more bids.
You're effectively saying that the global economy is also a scheme. I wouldn't disagree with that, it's just that what you're describing isn't unique to bitcoin.
It's not. It's built on increasing productivity.
Would you say eventually everyone who wants dollars will have enough and the demand for new dollars will be zero?
No one needs to use bitcoin. Its demand is chiefly speculation. It has very little use other than a speculative vehicle.
Something may become meaningless over time if the landscape changes to undermine the reasons for existence, but that underscores the point that 'reason for existence' is another way of saying 'it means something'.
Bitcoin's reason for existence was the bank bailouts of 2008. It has found supplemental reason in the current economic climate of quantitative easing. That means everything.
"Having a reason for existing doesn't mean anything" is an absurd statement.