Yeah I definitely cherry picked a convenient time period. But the point is that most people want a stable currency. Predictability is a good thing with money. Bitcoin has never been stable or predictable.
A deflationary currency (like long term bitcoin) is great personally, since why wouldn't I want my money to be worth more tomorrow than it is today. But in the macro sense, we really don't want that. If my personal money is worth more as each day goes by, my incentive isn't to go out and spend it on useful economic activity. The incentive is to hoard your money and spend as little as possible right now since things will get cheaper the longer you wait to spend. Deflation is a situation where the rich get richer by doing nothing.
So from a societal perspective a currency that deflates over time, like bitcoin, is a currency that discourages spending, discourages economic activity, and concentrates wealth into the hands of those who already have large reserves of capital and don't invest it into new ventures.
Bitcoin might make a good investment, as you pointed out it is up 1000x in 10 years. But that volatility is what makes it a poor currency. That rise was unpredictable, and for every huge deflationary period (price rise), has had an almost as big inflationary period.
You're right, currently the volatility and deflationary aspect does incentivize its use more as an investment than a currency, but there are some unique aspects which make it more desirable as a currency. For example,
No foreign exchange required. It is decentralized so no need to exchange it with any 3rd party.
Flat transaction fees. You can transfer $1B of value to anyone in the world for a buck. How else would you do that?
Theft protection. It's as safe as you want to keep your private key, you can even use multisig to get other people involved.
Privacy. There are many methods to make it anonymous, untraceable so others don't know you own it, how much you own, or what you spend it on.
A deflationary currency (like long term bitcoin) is great personally, since why wouldn't I want my money to be worth more tomorrow than it is today. But in the macro sense, we really don't want that. If my personal money is worth more as each day goes by, my incentive isn't to go out and spend it on useful economic activity. The incentive is to hoard your money and spend as little as possible right now since things will get cheaper the longer you wait to spend. Deflation is a situation where the rich get richer by doing nothing.
So from a societal perspective a currency that deflates over time, like bitcoin, is a currency that discourages spending, discourages economic activity, and concentrates wealth into the hands of those who already have large reserves of capital and don't invest it into new ventures.
Bitcoin might make a good investment, as you pointed out it is up 1000x in 10 years. But that volatility is what makes it a poor currency. That rise was unpredictable, and for every huge deflationary period (price rise), has had an almost as big inflationary period.