"BTC is doomed to fail by 2040 as fees won't be enough..."
Honestly, I need BTC to succeed at least until a new monetary system is in place.
BTC is ideal for this transitional period.
After that, $ETH, a new system, or something entirely different will present great opportunities.
I don't know what the role of BTC will be in the new world order, but we'll need to have an open mind and adapt.