Another thing is that Swiss Francs can be stronger than United States dollar, but it still has fiat characteristics which is long term devaluation, bitcoin will be the opposite of that.
I've looked at the stats and there was 0.5 % inflation per year in Switzerland between 2003 and 2025. This means you're correct: there is still a small value loss (to be precise, 12% in that whole timeframe). If you held CHF in the US your loss was lower (a little bit less than 10%) but still the Franc didn't manage to outpace inflation.
What's also interesting is what happened to the CHF's supply: its M1 grew a lot (from 250 to 750 between 2003 and 2023) but in "waves": first in the 2010-13 Eurozone crisis (when deposits in CHF was massively used to escape the Euro's devaluation, so a M1 expansion "made sense" as it matched its growing demand) and then the COVID crisis. From 2022 on the supply was stable.
Of course one has to take into account that the Swiss Central Bank on purpose increased its supply to avoid deflation and match the growing CHF demand. That's something impossible in the case of Bitcoin, but the massive demand increase between 2009 and the late 2010s was somewhat countered by the high Bitcoin emissions in that era (first 3 halvings).
Currently we have around 0.8% supply inflation per year in Bitcoin. This is interestingly close to the Swiss Franc's devaluation in terms of value, but that only has relevance if the Franc 1) continues to be as stable as now and 2) doesn't expand its supply again massively.
No one is going to be interested in Bitcoin if they can earn more from savings accounts, time deposits, and money market funds.
I think there is a logic problem with your sentence. If the Bitcoin price really grows 2% per year, this means that there is enough demand to sustain that price. So there are people interested in it, by definition

Of course if we don't reach the "currency" state which is of course a real possibility (as you point out) then what may happen instead is a period of low growth (sideways market or low ATH increase, like in the case of Ethereum or Solana) with high volatility, and that is indeed a "dangerous" scenario for bulls.
I don't think it would mean the death of Bitcoin. Gold has shown that even a 20 year long bear market (1980s-2000) still leads to some interest and then again very bullish conditions. But as Bitcoin lacks Gold's tradition and age, in such a scenario I would expect a sharper crash, but always with the potential to turn bullish again.
The "currency scenario" would be, in my opinion, very positive also for Bitcoin bulls. Bitcoin can't grow infinitely by influx of speculative capital, as speculative capital needs returns and like you say it would flow out if the returns are too low. If we see an evolution towards currency usage, I'd expect however a transition stage between "digital gold" and "Swiss Franc", where the returns would still be attractive but the stability would continue to increase.
As I wrote before I see some more currency usage than 5 years ago, but it is too early to say if this tendency can continue or if it was only a consequence of a combination of effects (like the COVID lockdown "digital boom" and the general digitalization of payments, and also the 2023-25 bull market).
Why do you write this like you're the first person to come up with the equivalence? People have been comparing bitcoin to gold for 10+ years because the connection is obvious.
In the case of gold this wasn't my intention, I even mentioned in the OP that "digital gold" is a popular narrative, and it's almost as old as Bitcoin

But the "digital Swiss Franc" scenario is indeed something new, I have before googled it to see if someone came up with that analogy. I have only found articles and videos that Bitcoin was becoming the "digital Swiss
bank" [1] [2], which is something different because it is more related to privacy.
[1]
https://www.ynetnews.com/business/article/b1pdt2zlxl[2]
https://www.youtube.com/watch?v=kqsmCUo3xEQ