Quite disingenuous for him for him to say that Bitcoin lacks improvement and that improvements should be applied sooner(which going the slow route totally justified, because you know, $700b marketcap, hence we really can't afford to screw this up); knowing that Cardano itself is known for taking the slow heavy-researched route in terms of development to make sure that the updates have no bugs and such.
Exactly, his ADA has taken a slow step on improving it's performance, so it doesn't make sense for Charles to say that bitcoin lacks improvement because as a dev, he should know that it is not easy to make iterations especially as bitcoin is a prime mover in space.
Bitcoin can still be sound money for majority, store of value, an assets. And yet with that argument that there is no development, from average joe to whales to huge management asset funds, bitcoin is still the king. Maybe he just wanted to shift investors to his ADA in a subtle way.