I think we have a very long time until that happens.  

I remember when I was first learning about bitcoin in March 2013.  People would say how this alt coin was better because it had faster block times, or that alt coin was better because it was proof-of-stake and used less mining energy.  Or this coin has demurrage to prevent hoarding or that coin uses ASIC-resistant hashing, or this coin is "Turing complete."  What I've come to believe is that this was mostly attempts by alt coin pumpers to appeal to newbies.  It seems to make sense that a "second generation" coin would be an improvement, but the more I learn, the more I believe that there are no fundamental improvements that can be made by alt coins and design changes.    

I've now spent months researching bitcoin at the technical level and I never cease to be amazed at Satoshi's genius.  He seemed to give great thought to every detail.  

My only criticism (and perhaps I'm missing something) is the way the ECDSA signatures are included in the transaction hash (which contributed to the transaction malleability problem).  But maybe there was a reason for this too that I've missed.  Nevertheless, we should have malleability eliminated over the coming year.