This is strictly speaking not true. Yes, the current implementation is not good for taking micropayments, but it never was designed for this. If you thought this, you misunderstood the scaling architecture of the paper. It was always likely an off-chain derivative was going to be necessary for that to be a thing (Lightning Network), even before the rise of and prediction of ASIC miners and explosion in general computing power making the original algorithm chosen look... not ideal. We just got here much faster than people originally predicted, which is about what you get when you try to predict computing power curves as a linear function rather than a step function.
Whether it's undervalued at $14k isn't for me to say and I don't think anyone can truly tell you in either direction. But BTC has scaled as promised, just not as people would have liked. Then again, that's not BTC's problem, that's people not understanding BTC from the beginning.
It has a very prominent role in pseudonymously exchanging large sums of money near-instantaneously, securely, recorded in a global and publicly-auditable distributed ledger forever. There's a great number of use cases for this particular method of funds transfer, ones that I use today and many do and find a lot of value in it, even over other cryptocurrencies (for now). Would I prefer everyone take LTC and cut my fees down? Sure. 75% of BTCs problems go away if everyone would just activate Segwit too, but that hasn't happened either for whatever reason, so, it is what it is.
The number is going up and there's a fun tech-beats-banks narrative. I'm as bearish as you.
What role, and why is it uniquely well suited for that role?
Speaking for myself, back in 2013, I was excited by what I saw as its potential for micropayments on the internet. That is (and was) clearly wrong - it can't do the transaction volume, is too hard to safely acquire and use for most people, and is too volatile.
Its current role is "hype-y speculative security". I don't see a significant and long-lasting need for such a thing, or how bitcoin is uniquely qualified to be that thing.
> I would advise anyone to only invest in what they know.
What is it to "know" a thing? Put another way, what exactly makes it such that you "know" bitcoin? Put another way, what useful information is there to know about it? I understand the details of the whitepaper and the block-chain concept at a technical level, because I find them innovative and fascinating, but I think any translation of that technical with knowledge of its value as a security is illusory.
I'm honestly curious about this: I've gone from very bullish to very bearish over the last 5 years or so, while I've watched the population at large take an opposite course from indifferent and unaware to very bullish, and I'd really like to understand what I'm missing.