Bitcoin is an exciting idea as long as you keep clapping your hands and saying you believe, as it doesn't actually exist.
You're right. As long as you believe mathematics doesn't exist and doesn't rule our entire existence. bitcoin is like digital gold, there will only ever be 21Mn of them created. The first purchase made with bitcoin was a Papa John in Florida (I believe) from London which was approx 10k bitcoin for two cheese pizzas. Nowadays that's about $50Mn. So yeah, it's pie in the sky.
bitcoin can't be rehypothecated, it's decentralised, nobody owns the rights to it, even its creator Sakoshi Nakomoto remains anonymous. But don't lose your private key or you lose your money. The technology it runs on, Blockchain, is I believe the future of communication and the internet which is well worth a look at. I started a thread on Blockchain about 5 years ago and got zero replies, something that doesn't surprise me, so many people are unaware of its potential.
As for gold? I'd happily hold half a dozen sovvies because the economists I trust believe gold is vastly underpriced, as do I as there is too much paper (futures) issued and the true value of the metal will be realised.
These are both long term investment options. You're not going to make a quick buck, but you will, over time, make a good return.
Disclosure: in 2011 I had a hard drive that had 2400 bitcoin then worth approx £5k. My antivirus wasn't up to the job and I lost the lot, including my private key. My fault entirely, I should've takrn my coins offline.
Still, those naysayers will knock it, and that's fine. Just make sure you keep a note of you private key.