Fully agree with that, I don't think bitcoin is going anywhere. I just feel there are better systems but to the masses they simply think bitcoin and nothing else as money wont research into the other systems. If anything I see systems like Polkadot instead becoming side chains and offering faster transactions for bitcoin and ethereum instead of the core blockchains having to be updated.
For example I honestly wouldn't update bitcoin. It's proven the test of time as being secure. However there will come a day in the near future where I do believe a 51% could very well be possible and it would be done via a government up to no good.