I believe that bitcoin will retain its leadership in the cryptocurrency market. and Ethereum will not be able to surpass bitcoin.
In terms of the value, Bitcoin is a head against Ethereum but in investing, Ethereum is better than Bitcoin as of now precisely that Bitcoin has reached its limit and maybe yes that Bitcoin is hard to surpass.
Bitcoin is nowhere reaching its limit, however this year ETH is crushed, the bitcoin dominance is the proof, when ETH falling on its price the market capital will automatically be less and less by that bitcoin dominance increasing.
However, ETH could still surpass bitcoin, only if the total supply x price = more than what bitcoin capital is having now.