I do like Jontim as a ship, but like, in a really specifically angsty way:

I like them as two people who had feelings for each other at one point before the series even began. It was nothing overly serious, and neither one of them were really perusing the other, but if they had been asked out a date they would have 100% said “Yes.”

Of course, that never happened. Or maybe they did have one date and it was…fine, perhaps even good, but they didn’t find time to meet up again after that for one reason or the other.

Then the Season 2 events of the series happen. And there’s these weird unsaid feeling’s between them that make everything worse. Jon is trying to silently grapple with his newfound distrust of someone he used to daydream about, and Tim is really struggling with the fact that one of his crushes got replaced by a monster and his other crush is someone he’s growing to resent more and more each day.

And, honestly, part of the reason why Tim resents Jon so much is because of his former(?) crush. There’s so much left unsaid. So many feelings left fractured that are never going to be put together because of Jon’s distrust. And Jon is aware on some level why Tim is so angry but…he doesn’t know how to fix things. So he doesn’t. And then he loses Tim in the Circus without ever trying to patch anything up, which is part of the reason he’s so desperate to fix thing with Martin in Season 4. He has the chance to make things right with someone else he’s grown to care for and this time he doesn’t want to squander it like he did with his former(?) crush.

So yeah I like Jontim, but I don’t personally mean that in a “I want them to be together and have a happy ending” way. I mean that in a “I want them to be a doomed "what could have been” that haunts the narrative" type of way.