Well, you mention that Congress can't get anything done even when dominated by a single party, but then you argue that their big failure is in their inability to pass legislation with veto-proof majorities. Of course, Congress has not, any time recently, actually been dominated by one party to the point of one party constituting a veto-proof majority. If your argument is that the legislative branch's failure is that the haven't united across party lines to exercise control of government with supermajorities that sideline the executive, then it is true that no such cohesion has been achieved in Congress. But then the point about single party dominance seems irrelevant, and neither party has, by itself, had enough votes to override vetoes any time in recent history. There is a lot of condemnation of Congressional Republicans these days for not putting party aside and forming a common cause with the Democrats to take power from the hands of our manchild POTUS. It would be a very unusual thing if they did in fact do that, and could only even be imagined due to the sheer incompetence and unfitness of the President. I can follow any of these strands and it at least makes sense to me. But when you conclude, then, that we need a stronger executive rather than a more assertive Congress, you lose me.
It seems your argument is "Congress is currently weak, stupid, and ineffective, so we should just accept that it will always be this way" but then also "Even though the current President is terrifyingly stupid, childish, impulsive, ignorant, and suffers from dementia, we should keep giving the executive more power because in theory this could result in good leadership."