A biobetter might be less lucrative than a biosimilar if the former were only marginally better and the latter were substitutable, especially if a biobetter has to generate an entire safety/efficacy package and go through the BLA approval process.
The need for active marketing, which greatly reduces the profit margin, is probably the biggest drawback for marginally-improved biobetters.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”