No, this didn't happen at all. There has been no election yet, and polls are not elections, they're just random-ish samplings. The polls showed voters weren't very enthusiastic about Biden, but back in 2015, the polls showed that Trump was absolutely certain to lose in a landslide to Hillary, and that didn't happen. I do agree with the poll results this time around, but that's just my opinion and not at all backed up by an actual election, which we now won't have (since the election will have a different candidate). We'll see how well the new candidate fares.
>However indirect the mechanism by which he was ousted
This "mechanism" was not part of the government at all, and not really part of "democracy". It was just a bunch of opinion polls organized by mostly the press, and they influenced Biden to stop his campaign, but again this is not some central feature of democratic systems at all. The only way of truly assessing what candidate voters choose is to have an election. Everything else is just guesswork.