Why would I want to keep BTC in my investment portfolio? That's most hyped and quite overvalued coin I'd say.
There are other more technologically advanced coins. Is it because of "digital gold" and store of value properties?
Yes, that's the point, Digital gold.
All about digital are new ages, futures. We hold bitcoin because it will accepted in many countries soon or later. Which problems about network characteristic, volatile, etc. It will find the way about how to regulate it. As we trust, bitcoin are new way to saving gold into wallet.