> mostly non-existent Russian interference
This is not true. The Republican-led, bipartisan Senate Intelligence Committee found, over the course of their 3.5 year investigation, that there was in fact Russian interference. You can find the actual report (all 5 volumes) here [0]. Alternatively, a TL;DR summary can be found here [1].
> amazing how they didn't somehow swing this latest election
Let's for a moment, assume that the Russians were indeed behind the interference campaign. Having experienced many Democrat and Republican administrations, they would know that neither side of politics has historically been favourably predisposed to firstly Soviet and later Russian geopolitical ambitions. So, why would you bother getting a particular party in power, if both parties present have always been on a unified ticket against you? Answer - you wouldn't. It was never about getting a particular party in power, rather it was about weakening your enemy's unity. In this case, Vladimir Putin can absolutely pat himself on the back, and more than any other world leader in recent decades, truly declare, mission accomplished (if it was indeed a mission). For all Biden's talk of unifying the nation, there is no way that the all of the millions of Qanonistas left scratching their heads over the absence of "The Storm", are going to go back to quietly accepting a two-sided status-quo. The chaos monkey in chief has successfully taken the raw material of a discontented working class, and using tried and true methods [2], shaped a potent political weapon, who importantly now realise they have power. There are now millions of chaos monkeys at loose within the Republic. If that's not a win for enemies of the US, I don't know what is. Do we know for sure whether this was part of a Russian long-term psyops play? I doubt we'll ever know. It's my view that the vast majority of those at the top of the power pyramid in place over the last four years, are almost certainly not Russian operatives or plants or had anything to do with Russia. What they were (and are) is hungry for power. Seeing an opportunity to implement their wet dream neo-neo-con agendas by riding the dragon, they went all-in weakening people's trust in institutions, science, evidence, truth. They were, as Putin might smilingly say, useful idiots. This is my view. I don't believe I'm alone in holding this opinion. But at the end of the day, it's speculation - another conspiracy theory. It's entirely possible that this was a coincidental but very happy set of circumstances for Putin. Either way, it's an outcome that reflects the fact a significant number of people close to the levers of power, played themselves into a position that suited them, and also conveniently suited someone else.
[0] https://www.intelligence.senate.gov/press/senate-intel-relea...
[1] https://www.reuters.com/article/us-usa-trump-russia-senate-f...
[2] https://www.azquotes.com/author/5626-Joseph_Goebbels
[2 Note]: This is not a glib Nazi reference. I believe that many of these quotes represent political axioms, and that those that understand them and are willing to implement them, can, and historically have, achieved great power.