It is not a theory that a Wyoming vote is 3.25 more powerful than a Michigan vote. It's a mathematical and statistical fact.
The founders never intended for women to vote or black people to vote.
The founders pretty much didn't intend for non-property owners to vote.
This isn't about the weakening of federalism. The Constitution was written when people at the time considered themselves more as citizens of their states and only secondarily as a citizen of the USA. That attitude was evident at the outbreak of the civil war. The compromises made AT THE TIME to get the Constitution to pass were necessary AT THE TIME. But those compromises should not constrain us 240 years later from improving our democratic system. This isn't 1790. Now, I doubt nobody, but a few cranks like some Texans, consider themselves first and foremost a citizen of their state. We are all Americans.
The 10th Amendment argument is also specious. What the founders got REALLY wrong is the worry that the federal government would trample on citizens rights. In fact, it has been state governments which have trampled on citizen rights far more than the federal government has! States rights (10th amendment) arguments have been used by states to implement Jim Crow, violate right to vote, and more. States, instead of laboratories of democracy, have actually been laboratories of repression.
There is ZERO reason that the presidency must be voted in via the EC. The founders ACTUALLY intended for the EC to be completely independent of the voters. Electors could literally vote for whomever they wanted and were NOT constrained by the will of the popular vote. We don't follow that intention either.
When I vote for my governor, that vote isn't filtered by an 'electoral college' nor does my state have representatives allocated to counties rather than drawn districts.
Your arguments are simply circular arguments and the "the founders intended" argument is merely cover to prevent actual democracy from developing. We want to work towards a more perfect union. To do so we enfranchised women, enfranchised minorities, expanded voter rights.