Firstly OP, if I may ask, is there an asset, commodity, currency (infact anything tradable) that's ever stable? I believe not.
Well, there has never been and will never be any asset that will be perfectly stable. The only thing you can say is stable is that 1 BTC will always be worth 1 BTC.
But other currencies, like the USD, has much more stability than Bitcoin does. Bitcoin is volatile, while the top fiat currencies are somewhat stable.
Bitcoin is not stable due to lots of factors. The major one imo is immaturity. Had the market been mature, we would've had a less volatile cryptocurrency. But honestly, we only have a few cycles that only
might repeat at some point so we have no idea whether Bitcoin has its own cycles or goes against the standard. There are some typical cycles in our economies, like recessions that happen about every decade.
But BTC is way too young for us to know for example if the post-halving booms will only happen in the first decade of its existence or are an usual event. Then we should also not ignore that regulation is still foggy in many countries, which makes people a little doubtful about the idea of owning cryptocurrencies.
And then, we know that every 4 years Bitcoin becomes harder to be mined. That on its own makes Bitcoin more volatile than other assets. You have no idea right now
exactly how much gold there is left to be mined. With BTC, you can count every single satoshi perfectly.
Only time will tell if Bitcoin has to become something stable or not. I doubt it'll ever be though.