The way Bitcoin works simply doesn't allow it to be stable. If you're looking for something stable, Bitcoin just isn't it and the past shows it quite well. And tbh, I think a lot of people would lose interest in BTC if it became stable. It's one of the most fascinating things about it.

Fees can't be "normalized" if more places start accepting Bitcoin. When demand/number of txs increases, the mempool clogs up. This is one of the reasons it is still largely considered an investment rather than a currency.

Well, I think this is double-edged honestly. While there are some users out there who are using it more as a currency than an investment, we have to think of potential consequences of it becoming more of a mean of exchange than anything else. I don't think we have any fiat currency today that is volatile, so paying for stuff isn't a mess in our daily lives. But Bitcoin is the opposite - imagine paying for an online order worth $1k while Bitcoin's price increases substantially. Before your tx gets confirmed, you'll want to use RBF to get back your money as you now basically have a pending payment worth way more than $1k.