We see that's some of the cryptocurrencies ranking level are decreased such as dogecoin before it was ranked #4 but currently I think it doesn't listed even in top #10 ranking... So can bitcoin also decrease its rank in the future or it will remain #1 rank forever?.
Theres no such thing about lasting forever but we can actually tell that bitcoin would still have the long run to remain the top spot.Why?
We know on how big the bitcoin community is and also this had been the first crypto ever created and been supported by the masses thats why
its really hard to believe that it can be replaced by any alts in the market no matter how new it is when it comes to specs.
Lasting forever wont be the issue here but if this one would be worldwide be adopted then that possibility or chance is still there.
we are only talking about ranks and not the death or how long the coin will live . still i agree on what you said , btc is too mighty too get knocked down on the top spot but other coins are always possible to get de throned .
for example doge coin because doge coin is pretty weak so its normal for its ranked to fluctuate because there are also coins that are becoming good overtime . let say if btc ever de throned on the future , i think many are still going to support it becuase other unranked coins still have supportes too .