BTC in this early stage currently offers more than just being a store of value

Currently, BTC is not just a store of value, but at the moment also a very strong value grower.

Thats why many people use BTC as a value grower like you would use a diversified index fund. Many people don't just use BTC to only keep their purchasing power – they can also benefit from real purchasing power increase because they are still early.
I think once bitcoin gets more adapted worldwide and gets worth multiple millions per coin in the next decades, this purchase power increasing trend will slowly fade away, its value will remain more stable, so thats when it will just be a store of value.

Thats the moment BTC won't get used like an index fund anymore, people in the future will have to invest in stocks (more risky) if they want to increase their purchase power instead of just keeping it. If they just want to keep their purchasing power without risk, BTC will be for them.

But thats not the time we are living in right now, at the moment BTC still has big chances to multiply your purchase power.