Well experts say that Biden has a good chance of winning if he runs against Trump. In fact, Allen Lichtman has predicted every election correct since 84 except Bush vs Gore. But that was due to Florida fucking with the votes. He himself says Biden has a strong chance of winning if Trump is picked as the Republican forerunner. Which they obviously will pick him.
The problem with 2016 was that Republicans clearly couldn't take having a black president for 8 years to then go and have a woman be the next president right after that. Then Trump who just said any and everything to appease to then crazies of this country and they came out in droves. As well, Hillary just wasn't that charismatic in her debates
It could just be me, but from what I've seen of those around me as I'm Gen Z myself, a lot of us ARE aware of local elections and how important they are. We actively do vote in them. It may have a much bigger impact the next go around but we'll all have to just wait and see