My opinion is that in time Bitcoin market share will keep reducing, as many other coins and tokens and platforms will keep surging.
In the long term, the blockchain technology is very disruptive. Bitcoin will more likely compete with Gold, Ethereum will provide a backbone for many uses.
So I am not really sure a collapse is incoming, it depends if a real bubble will quickly form.
You seem to be saying two things, and correct me if I’m wrong. Firstly that you think bitcoins current 37.5% dominance of the market cap will continue to fall as other blockchains disrupt the world and replace its use as a cryptocurrency and it becomes mainly a store of value only, and secondly that you see the cryptomarket collapsing and bitcoin price at risk of collapsing further if the market is in a bubble or one forms.
I certainly agree that the later generation blockchains and protocols being developed will in turn allow the development of dApps that will slowly replace the current massive centralised companies and businesses we all use over the next 10-15 years in a third major technology revolution of the world. I disagree however that use of bitcoin will become redundant over that 15 years, and in fact I see the opposite happening with bitcoin continuing to be the most important cryptocurrency in this new world for payments as well as an increasingly important store of value as you say. And I say this for several reasons. Firstly while bitcoin had problems with Tx speed and costs late last year, this was only because of the unprecedented heavy demands put on its network at the time which are magnitudes bigger than any other cryptocoin has ever faced - and in fact the bitcoin network which has never been hacked or compromised coped quite well and is now running smoothly again! And to cope with increased demands on the bitcoin network with the next big run up in price and its adoption and use by more of the population, the 200+ dedicated developers working on the bitcoin network (which compares with the 10-20 developers typically working on other blockchains) are finalising 6 major exciting improvements to the network that will improve its robustness a lot! Secondly bitcoin is the recognised ‘face’ of crypto, and its recognised by >50% of people in the world many of whom are interested I owning and using it - and buying it will continue to be the entry point for most new people coming into crypto! And given its limited and fixed supply i believe its value will continue to increase exponentially much as it has for the last 8 years, as shown nicely in a linear fashion in this log-graph i recently constructed of bitcoins price from 2010 to early 2018 -
https://imgur.com/gallery/9iF3t . The linear exponential growth for the last 7 years is extrapolated out over the next 7 years in the log-graph giving values of bitcoin in the hundreds of thousands, and while it’s very important to remember that a projection of past behaviour like this is in NO way predictive of what will happen in the future I do believe that the positive factors I’ve mentioned will lead to increases in bitcoins value like seen in the graph as its ownership and use by people increases from the current <1% of people who own or use it to 10-15% ownership and use over the next 5-10 years - and I think it will hold its place as the most valuable cryptocurrency over this time with at least 40% of the market cap.
And as you can also see from the log-graph the bitcoin price shorter term goes through big speculative upwards runs and then crashes and moves sideways, with the periods each lasting 12-24 months. We are currently 6 months into a period of bitcoin having crashed 60% from its Dec 17 ATH and it moving in a sideways fashion at ~$8-10K, which will probably last for another six months before the next major upswing takes it to a new ATH of $50K in 2019. And my feeling is that we are at the bottom of this market crash since Dec 17, and that we won’t see bitcoin collapse under $7K before the next bull market fuelled by institutional money and another 1-2% of the population FOMOing in to buy bitcoin first and then other altcoins in the next major upswing. But there’s no guarantees in investment or life of course, and theres always a small chance that the whole crypto space may become worthless which is why people investing in crypto are told never to invest more than they can afford to lose! Good luck with your investing!