So, you'd rather have a never ending Obama presidency? You felt he was the best president in your lifetime?
I did NOT say or even imply a "never-ending Obama presidency". Please refrain from putting words in the mouths of other people.
Looking objectively at what he accomplished in the context of the obstacles he faced, Obama was the fourth-best president we've ever had (following Lincoln, Washington, and FDR in that order). Obama not only took over smack-dab in the middle of the worst economic crisis since the Depression (we lost 700K jobs just in the month he took over, remember), but also while we were mired in two highly-unpopular wars, both of which were then among the longest wars in our history. He was certainly not perfect - no president ever has been or can be - but by the time he was done, one war was ended, the other was decreased to a low-key occupation, America had been given the longest stretch of private-sector job growth in our nation's
entire history, our budget deficit had been cut in half, led the entire world to join in the Paris Accord to address climate change (it didn't then but now does include Syria and Nicaragua, AND the Accord endures worldwide despite the worst efforts of Trump), and more Americans were covered by health insurance than at any other time in our history...
...and he did all that while enduring the worst political opposition faced by any president since Lincoln.
Back to the Paris Accord for a moment - in human history, all the world has banded together to face a common threat only one time before: the
Montreal Protocol which banned the CFC's that were destroying our planet's ozone layer. As Big Oil does today against climate change (and for the same fiduciary reasons), the chemical corporations (led by DuPont) tried to fight the Montreal Protocol...but it was passed, to the benefit of all of us. The effort to pass the Montreal Protocol was led by the UN...but the leadership that led to passage of the Paris Accord was Obama's. I know of no other president that can point to having led essentially the whole world to agreement on any single major agreement.
So...yeah, objectively speaking, Obama was a truly great president...and that's how he will be remembered by historians. You can claim otherwise all you want, but those are the undeniable facts to which the historians will point as justification for his status as a great president.