if what cafu said was true about the ability of btc's algorithm to completely change or modify via this "fork" then what is the point of using altcoins at all if u have the capital to dump into btc?
A hard fork sounds simple (it's simply a software update with incompatibilities respect to older versions) but in the case of Bitcoin it is a complex operation, because the Bitcoin community itself is complex and there are many views and interests, some of them conflicting.
Take the current Segwit "war", for example. We have had a stalemate over two years because two groups (some developers and some big mining pools) could not agree on the way to update the software.
So I think there will be much space for altcoins trying out things that are controversial or experimental. In this case, if the altcoin proves to be better than Bitcoin, it could attract a part of the users and the ecosystem (businesses, merchants etc.). And then the possibility of a "takeover" and a declining usage (and as a consequence, price/value) of Bitcoin itself does exist.
also yes exponential growth on an infinite timescale ofc is impossible but over lets say a 10-20 or even 50 year sample size what would really slow down the overall long-term trend in growth if you can still assume my basic assumptions.
1. The people who know and use bitcoin will only go up
2. Bitcoin's foundation and core design principle of blockchain only improve and the public's understanding of how it works will only improve
while you are spot on about the possibility of these negative feedback cycles wouldn't these cycles either decrease or even possibly be NON-EXIST once better exchanges, more consumer friendly regulation, legal framework are finalized and then perfected over time?
It's definitively possible that there won't be negative cycles in this case. But here you are already assuming a best-case scenario. Legal framework, for example, can get worse or more complicated because of interest conflicts in governments (cryptocurrencies put in danger some of the business models of banks, but governments have often close ties to banks).
But the worst scenario for Bitcoin would be a better technology that makes it obsolete. It could be another cryptocurrency with better scaling, less environmental cost etc., or - even worse, because then no hard fork is possible - a new currency system based on complete unknown technology (e.g. artificial intelligence?) or even an economic system which works in other ways than current "money", which is a pretty simple tool.
I just don't see how human beings would stop innovating, [...]. Now with AI making philosophers re-defining/re-thinking the term "sentience" and "self-awareness" as well as theories such as
https://en.wikipedia.org/wiki/Flynn_effect being better understood I don't see BTC being replaced anytime soon especially if the algorithm is as adaptive as that one user said it was.
I am also relatively optimistic about innovation, but Bitcoin's scaling problems have shown that there could be certain limits that could not be solved in the next 10 or 20 years if we don't want to sacrifice decentralization.
Also this doesn't even take into effect breakthroughs that we've seen throughout history that have led to massive betterment of living conditions for everyone in the world.
This "betterment of living conditions" is an interesting point: What if many of the basic needs of humanity can be solved without any intervention of money - e.g. if food after further technology advances being so cheap to produce that its basically costless? What would be the price of Bitcoin if that scenario applies to more fields, e.g. housing? But even if Bitcoin would crash in this scenario, wouldn't it be a better world than today?
That are all complex questions, but that is the reason why I don't think we can now predict that Bitcoin will grow forever, or even for the next 20 years. I for myself am pretty bullish for cryptocurrencies for the next 5-10 years - in part, because of the mechanisms you cite in your theory, e.g. better knowledge - but I can't predict what will happen in the long term. There are too much variables.