So what would the perfect coin look like? What sort of technology, abilities, and specs would the perfect coin have to have to overthrow Bitcoin and all others and be the only crypto currency we could ever need?
You might have got extraordinary imagination power, that is the reason you are trying to imagine beyond bitcoin. Bitcoin must be the only technology we all need for ever and most other coin will not be surviving for another decade too. Because, bitcoin may incorporate all the features of those coins are providing either within its blockchain or through having a third party services. You cannot expect bitcoin to be replaced by another coin in any time because if that will be happening that must be an alien thing which is not a realistic as per today's science (just trying to match your imagination 
).We know that Bitcoin is not created for every specific use.
What other things you are expecting from a currency ? Bitcoin is a currency and it is a versatile enough to serve us as a currency. Blockchain technology might be helpful for various other applications but that does not mean bitcoin is useless due to other specific use cases.