bitcoin's value is based on its monetary properties and less on its technical qualities. as long as it functions as advertised then 'good enough' is a powerful incentive to keep refining it. it only has one job to do.
ethereum is of course huge too, but its fundamental value proposition is utility. it's effectively a software platform, not money.
since that's the case then is the case for it being usurped by something that does the job better higher than bitcoin?
if something that doesn't require learning a new language, is much more foolproof, that addresses scaling and blockchain bloat comes along with enough oomph does it have a shot at unseating ETH or is everyone now incentivised enough to make ethereum the one?
personally i don't think ethereum's future in fully in the bag and people are learning more and more every day. what do you think?
I think in both situations you have to regard Bitcoin and Ethereum as a network. The more people join Bitcoin, the more valueable the network is, the more people build on Ethereum, the more valueable Ethereum is. I wouldn't say Ethereum is too big to fail though, there are certainly alternatives that work really well/better in some aspects and since its all quite early we might see less companies join Ethereum in a few years and more companies use other blockchain platforms, as there are more companies coming out that connect existing infrastructure (blockchains) it wouldn't really matter to a company to use Ethereum or another blockchain as they can still communicate with their client thats on another blockchain. So we'll have to see. Ethereum has potential though to outgrow any other crypto including Bitcoin, but Bitcoin has relatively low competition as opposed to Ethereum. Most people see Litecoin for example as complimentary to Bitcoin and Bitcoin Cash isn't taken very seriously (though I personally think we will see more of them). But with BaaS platforms we see clear competion.