Luis, I remember the Obama years VERY WELL, although I suspect that you may not. In the narrow window when Obama had majorities in the House and Senate, the administration got Affordable Health Care passed. That benefitted millions of people.
Now, about that suppposed majority. Ted Kennedy, the Democratic Seator from Massachusetts was ill with cancer from 2008 until he died in August 2009. He was, sadly, replaced by a Republican. Al Franken, another Democratic Senator, was in a long recount battle, and he was not seated until July 2009. In the meantime, the Republican incumbent remained Senator.
Believing that they had gotten the job done, Democrats stayed home in 2010 (hey, Obama's in office, and "it's only the midterems") so Democrats took a drubbing in the House. Thus began the moves to thwart EVERYTHING that Barack Obama proposed. Obama was re-elected in 2012, but not having learned the lesson from the 2010 midterms, Democrats AGAIN stayed home, and we lost the Senate. I can only imagine Mitch McConnell's bodily reactions when he realized that he was Senate Majority Leader.
Again, you will recall that given majorities in the House and Senate, the Republicans had an absolute field day thwarting the administration's every proposal. You may not know this, but the House and Senate even refused to allocate funds for repairing the Capitol dome, when chunks of it were falling to the street below. Yes, they were that petty.
The lesson is not that "nothing happened in the Obama years," but that if you don't hold both houses, most particularly the Senate, which is the body that approves judges, you may as well twiddle your thumbs. The Republican Senate majority, always in lockstep with their leader, allowed McConnell to deny Obama his Supreme Court pick. There is NOTHING that Democrats could have done about that.
Boy oh boy, Democrats can be slow to learn their lessons. In 2016, many Democrats stayed home because they didn't "like" Hillary Clinton, or they were bristling over Bernie. We brought that on ourselves. Given that Trump was thee Republican candidate, we really didn't have enough sense to get to the polls? Now, if you can prove me wrong, not with generalizations, but with facts, then I am eager to have you do so. I look forward to your considered and fact-filled response.