Hot take: S2 Jeremiah is worse than S3 Jeremiah
Now I know this is a bizarre hill to die on, given the shit he pulls off in the last season, but please bear with me if you want to. This is a long rant.
S3 Jeremiah is deeply insecure, resentful, careless, bitter and very, very afraid of losing Belly after he basically built his life and self worth around Belly "choosing" him over Conrad. He partakes in self destructive behaviour, keeps poor company and has formed a codependent dynamic with Belly where both their issues had stopped them from realising their true potentials and becoming evolved versions of themselves they were meant to be. The college bubble of blissful ignorance, denial and non-confrontation with fundamental issues had provided them a brief comfort haven, but once the reality of adulthood came crashing down, it became clear how fundamentally incompatible they are with each other.
My thing is, S3 presented all of these issues both with Jeremiah as an individual character, and in his dynamic with Belly so clearly that *most* of the audience identified these flaws in him, even if characters weren't directly calling him out. This makes his writing cohesive and his character decently well written. At least until they shove a last minute 'redemption' without fully having him process the harm he has caused, or having Belly recognize that she wasn't the only one at fault in hurting jere, that she, too, was hurt massively by him. But that's the subject of another rant.
Now coming to earlier seasons, it isn't like all these character traits weren't still there with him or in his dynamic with Belly, but the show, esp in S2, is so fixated with the idea of him being the 'endgame' for that season, that they totally brush over his flaws and complexes from S3 that are still very much...there. People often say "s3 Jeremiah was bad, but S2 Jeremiah was actually mature, he told Belly he won't mind if she chooses Conrad. That he's okay with being friends with her".
But this framing completely erases the fact that he says this to Belly in the literal last FIFTEEN MINUTES OF THE SEASON FINALE WHEN SHE HAS ALREADY ASSURED HIM SHE WOULD CHOOSE HIM NO MATTER WHAT CONRAD SAID! This makes his actions less selfless and more performative where the 'male lead' had to have a last minute show of self-sacrifice when he already knows he has won.
Now compare this to Conrad's good bye to Belly in S3 ep 8. He has no way of knowing that the wedding would be called off. He did a selfish thing in confessing his love, got scolded and lashed out- at by everyone for it, didn't back down from his confession regardless. And when both Belly and Jeremiah made it known that they don't want him around, he said goodbye to Belly, assuring her that loving her was 'worth it' for him no matter what, and that he wishes them both (not just her, but BOTH of them) a happy marriage! He doesn't have any way of knowing that Belly might give way, that he would be 'chosen' in the end, like Jeremiah did in S2. All he has is instinct and a clear, deep belief and pride in his love, and that was enough for him to keep going. This is a parallel to Jeremiah's situation in S2 last ep. Except he was assuaged at least a dozen times by Belly that she would choose him. So how am I to take it as an action just as selfless? What makes Jeremiah's case poorly written is that Jenny Han's intention was to have that moment be a big 'growth' for Jere, where he's okay to just be in Belly's life as a friend. But clearly he wasn't so unconditional and self assured in his love for Belly, because insecurities and resentments related to Conrad were never really processed, and they came back in S3. You can't pronounce a main character's arc complete, when the story is mid way😭. And TSITP ppl forgot this when they wrote Jere in S2. At least they aren't beating around the bush with his flaws in S3 like they do here.
It is often said "Jeremiah is only trying to protect his heart after what happened in S1 to him. So he's completely right in being angry at her". But this is really only half truth. In s1, not only was he aware about Belly's feelings for Conrad but Conrad's for her too. Heck the show actively makes a choice to SHOW a presumably "sunshine, golden retriever" second male lead resent the primary male lead for reciprocating the main character's feelings...and then chooses to NEVER hold him accountable for that resentment! Many ppl in the audience don't take issues with the conniving he does in S1 and s2 because the show itself just skims through them as justifiable actions born out of his insecurities. It isn't like Conrad where his flaws would get hammered down, to the point you yell at the screen "I GET ITTT!!".
Jeremiah is the only party in this love triangle who has always operated with full information. But the show and characters themselves are so obsessed with seeing him as a "poor victim who got caught in the cross fires of epic bellyconrad love saga" that they don't let the story or Jeremiah, himself, come to terms with his own selfishness or bitterness induced acts of numerous sabotages. His final calling is to "learn to forgive Belly and Conrad" for his own sake and to 'love himself without attaching his worth to a third party." The latter is fine, but the former, against minimizing HIS role in the love triangle—presenting him as a hapless victim instead of an equal participant.