required a lot of times to build reputation and networking to make this happen
i stated clearly bitcoin is irreplaceable , nothing can switch it
the bitcoin community is the largest
only miracle and an altcoin breakthrough features could replace bitcoin
As of now, you are right bitcoin is irreplaceable and our community have the largest number in case of supporters but we can't stick to that word "only miracle and an altcoin breakthrough features could replace bitcoin" because we can't be sure that bitcoin will be stable for the next 20 or more years because we know that there is a event that we called halvening where the bitcoin block reward will be half and the mining difficulty will be higher and higher and so on. If that happens many miners will find a new one or another crypto-currency that can satisfy their needs both in profit and expenses. If they find another one that is giving much better income than bitcoin then they will push that coin and continue to support that new coin rather than sticking on bitcoin. Its all about stability and the profit that it gives and second is the features of a coin. We can't predict the future, So just enjoy on what we have now.
if then bitcoin cannot survive in the next few years
how can you say any other cryptocurrency will do? it's a simple logic
mining difficulty is not the real problem for people to leave bitcoin and start seeking for a new one i guess
every altcoin has a block difficulty, and if bitcoin diffculty gained , so do altcoin!
some people forget that when they are comparing bitcoin with an altcoin they should consider the same amount of usage for that altcoin. in other words the same amount of miners (hash rate) the same number of transactions, .... and most of the altcoins will fail because for example their blockchain will grow 20 times faster that bitcoin's blockchain and they automatically fail the first week.