It was semi intentional. It wasn't as extreme but the Senate was still a compromise for smaller states to have leverage in government and get them to sign on.
Meanwhile, the house is about 10 times smaller than what the founders envisioned. Maybe that's overkill but we probably should at least expand the house quite a bit. And Probably expand the supreme court as well.
I would argue then that the Senate is extremely overpowered. The disproportionate body should be a brake on the power of the government, not be the literally stronger half of Congress.
The fact that the most democratic part of the US government, the house of reps, is now the weakest part of the US legislature is ridiculous.
If we're dreaming up fixes, I'd say
1) Senate actions should require a strict majority. If anything should require super-majorities, it should be the House of Representatives.
2) The Senate should not be in control of appointments to the exclusion of House of Reps. No idea what the ideal system is there but the disproportionate body should not be more powerful than the proportionate body.
3) The Senate should be able to at most block an action for one term of Congress. That means that every Senate action can be overridden by an election. Which means the disproportionate body is effectively calling a referendum on legislation, instead of being a hard-stop.
the problem is that since 1911 the house has also been a compromise for smaller states to have leverage because it's capped at 435 total members regardless of population. we've gone from a system of dynamic tension between popular rule and representation for smaller populaces to a system where both houses are on the side of the "underrepresented" to an extent where they're actually vastly overrepresented. Combine that with the electoral college (which again allows a ruling elite to overrule the populace and advantages smaller states) and the fact that the elitist president and elitist senate pick the supreme court and you can see where the so-called "underrepresented" populations are actually the ones in charge of every branch of government.
This is, of course, exactly what the founding fathers intended. They disliked kings but they feared rule by common people and always intended there to be a privileged class of citizenry that does the actual ruling because people like you and me are just too ignorant to be trusted with that. That's why they excluded the vast majority of people from voting at all and those that were allowed to vote had their power diluted by various mechanistic means like capping the senate, flooring the house (and later capping it as well), using the electoral college to make sure that those precious few who vote at all don't vote incorrectly and having the least representative members of the executive and legislative branch select the judicial branch so that they're not swayed by "politics" (read: what the governed actually want).
And that's how we have a system that claims to be a democracy but where what people want is actually completely disconnected from what happens, and where "The opinions of 90% of Americans have essentially no impact at all" (https://act.represent.us/sign/problempoll-fba/).