I was not old enough to vote in 2016 but I was in 2020.
I would not wholly regret my vote. The reason being that Trump's administration, unlike Biden's, was actually very successful during his first term, at least regarding the economy, foreign relations, fighting sex trafficking, and immigration. So while this is a gigantic fuckup Trump still had successes to back him up, a.k.a the "capital" Gehenna keeps mentioning. In contrast, Joe "Most Popular" Biden was largely viewed as a sleepy background character during Obama's era (so no successes), and literally only ran on "I'm not Trump" and banked on TDS in 2020.
However at the end of the day, this would not have happened under Trump because he would've followed the plan he set up, so it's redundant. The Taliban evidently had some kind of respect for him as a leader, unlike Joepedo. Biden literally just acknowledged Trump's deal, in what is quite possibly the biggest shock this year.