It's not impossible, but it won't happen. Maybe there will even be a new coin or another coin that will surpass the BTC, but this coin is certainly not ETH. The economy, a structure that has already developed around the BTC, is enormous and this won't be affected so easily. There are many factors that inhibit current prices, but in 10 years if you have to bet on who will survive and still be number 1, betting on ETH is really being very brave.
Nothing is impossible of course, but realistically speaking it will be hard to surpass Bitcoin anyway. It could happen though because there is some intrinsic incentive to it. If Ethereum gets closer, there could develop something similar to self-fulfilling prophecy. The closer Ethereum gets, the more the people are excited to see Ethereum surpass Bitcoin.
The thing with bitcoin is that it's total supply capped at 21 million that without counting all the lost bitcoin meanwhile ETH total supply keep increasing day by day, just multiply the total supply with the price then ETH could have chance to surpass BTC in the future, but that's only if
BTC price stagnant, if BTC keep increasing and reaches $100K like people speculated, then it's gonna be even harder for ETH, BTC market cap could go up and down very drastically within short amount of time.
Total supply is one of the main factors and of course the demand because everything would really be varying or depending on it because no matter how big or small it is then it will still be varying with the support the community gives.Nothing is impossible here on crypto and nothing do last forever on the peak spot but basing and observing on how bitcoin perform since from the start until now after a decade then its really hard to believe on that it would be easily be
replaced by ETH but we cant also deny that ETH is really a good altcoin which did really have that significance into its existence.