However, this viewpoint misses a fundamental point. Altcoins don't thrive purely due to their technical features. In fact, their primary purpose isn't technical at all. Altcoins mainly serve to profit their founders and early investors.
I think the argument with drivechains killing altcoins is that altcoins can no longer use technical arguments to shill their altcoin.
I think most altcoins advertise themselves as technically superior but not the politics behind.
However, for this argument to work, we need to assume that the general public would be aware of drivechains on bitcoin and what they make possible. Which will probably not be the case since they already don't really understand the difference between bitcoin and altcoins.