You do have something of a point. If you look at the earliest setup there were 26 senators and 69 representatives, a ratio of 2.5:1. Now (assuming we count DC as 2 senators and 1 rep) we have 102 to 436, a ratio of 4.3:1. So the relative weighting given to small states is much less than originally.
CDs have been gerrymandered so very few are competitive. Would have to check how often presidential vote differs from representative vote but I suspect it isn't that often. Wouldn't we still be looking at a few "swing" CDs controlling presidential election?