there are checks and balances. It's that McConnell straight up abused his authority as Majority Leader to obstruct a nomination for well over a year. The Senate gets to advise and consent to a nominee, not dictate who it is. It almost seems like you think the proper solution is for Obama to nominate Neil Gorsuch or Brett Kavanaugh since that's the only way McConnell would so much as hold a hearing.

No, the Senate is there to check an unqualified or questionable candidate. Typically the process has been for the President to float a list of names and the Senate (if run by the other party) to screen out non-starters who are too extreme (Bork), have questionable character (Kavanaugh, although he was confirmed), or are unqualfied (Clinton had floated the idea of nominating Mario Cuomo). Typically consensus candidates have even included the likes of Ginsburg, Breyer, Scalia, and Rehnquist.

In the event that candidates are controversial, that is hashed out through public hearings and then resolved by vote. What McConnell did was a craven, chickenshit move to avoid the obvious: that his only real problem with Garland was that Obama nominated him and he wasn't a right wing nutjob.