Simply as an investment will always need to be quoted vs Fiat currency to measure success of the investment vs as use as a currency it is intended to be quoted in BTC / satoshis.
I don't see that as an issue at all. BTC doesn't need to replace fiat. It needs to be an easily available option alongside it, to keep it in check (and anyone who wants a well managed fiat should want that too). I don't really care what the unit of account is. There are plenty of wallets that will very seamlessly calculate the conversion when using whatever fiat currency as the unit of account.
What are some of the other top items?
Making further in-roads re. merchant adoption. It needs to appear in POS systems alongside all of the other existing payment options.
Greater levels of education re. bitcoin, how to store it, transact with it, etc. In El Salvador the government has gotten behind the addition of Bitcoin into the school curriculum, covering all of these basics. There's also an NGO running its own educational program there. Over the longer term, that will be meaningful.
The development of more of these community-based circular bitcoin economies is useful from the point of view of education and bringing BTC to ordinary folks in the developing world. Since those developments in El Salvador, similar initiatives have popped up in Brazil, Honduras, Guatemala, The Philippines, Vietnam, South Africa and Costa Rica. I'd like to see these develop further. Another couple of developing nations recognizing bitcoin as legal tender wouldn't hurt either (although the IMF is throwing its weight around, warning them all off taking this route).
I believe there's also a problem to be solved in terms of self custody. It's a feature and benefit but one that comes with great responsibility and one that these last couple of generations are not used to. We're used to having a centralized entity to fall back on when losing access to a system. There needs to be a manner in which this can be tackled to ensure self custody while taking the risk of losing access out of the equation.
User experience needs to improve also in terms of wallets. And as regards Bitcoin's layer 2 (Lightning), there are plenty of issues that have yet to be ironed out.
Network effect can be difficult to achieve but so long as that network effect is expanding (as it has been), then it can get to where it needs to be. I'm fully on board with the use of bitcoin and based on the part of the world I'm located in, to use it more frequently would be very much worthwhile for me (much less so if I was in Ireland). But I need more people using it - so that I can use it more. It's like the roll-out of the phone back in the day. If you and I had a phone but nobody else did, then that's useful but not that useful. If everyone has a phone, then its exponentially more powerful. Network effect.
If more folks hold a little bit of BTC in a digital wallet, then dependency on exchanges will also fall - as at that point, people can exchange it between themselves with much more ease.
Demographics also plays a role. I had someone approach me recently - wanting to know how he could move $ from one country with capital controls to another country with capital controls using bitcoin. The guy was 60 and not technically savvy. I told him to do it the old school way and walk it in, which still left him with plenty of red tape on the other end (because otherwise I'd literally have to do it for him and that wasn't practical, nor did I want to). The money was clean but folks in Ireland have no idea what nonsense exists in developing world banking systems (which is very relevant in terms of use case for bitcoin). Imagine he had to make four cross-border journeys to do this - the time that took, the security risk and the cost?
The generation coming up behind us will be entirely digitally native. That makes a difference and with that, I believe that it will be much easier to bring about adoption via that demographic.
