Thanks
Bitcoins limited quantity makes it more valuable but even it has a limited supply we can't use it in the future. Inpact there there is a bright future in bitcoun because as time goes by the value of bitcoin will increase more and more as long as there is a lot of demand after a couple of years or until future comes.
Why is more valuable? Why - in the next future - people must buy our BTC?
Quantity is not a problem at all. (as said above it's advantage). BTC is divisible and now we use 8 decimals (satoshi) but can be more if necessary.
Capacity is the issue ( possible number of transactions per sec. ). Blockchain can handle around 4 txs/sec ... that's pretty far from thousands txs/sec done by visa etc.
As of value. No one "must buy them" but if he wants BTC then he have to mine or buy (alternatively steal/seize).
I valuate BTC because of it's properties (predictable supply, crossborder usage , p2p...) and especially because of the limited amount.