It’s always so heartbreaking to me that every time we see Owen display how he really feels about Luke in canon (the books, and Kenobi) Luke is never there to hear it.
When Owen faces down the inquisitor and declares that Luke IS his son, Luke is already way out of earshot (even though I do sort of consider the Kenobi show non-canon). When Owen talks to Beru after the argument with Luke on the day they die, telling her he feels bad about having to squash Luke’s dreams and wanting to find some way to make it up to him, he never hears it.
Owen’s relationship with Luke WAS complex, and it was rocky sometimes. I’ve always read this as Owen having difficulty being emotionally open, at least as far as the ANH novel and Kenobi show have shown. Owen loves Luke DEEPLY, right to his core. But he doesn’t know how to put that into words. He’s an awkward man! He’s been raised on nightmare hell planet where becoming too attached to someone might end up in them being killed or sold into slavery and you being miserable! Look at what happened to both of his mothers!
When someone you love dies, you look at all their actions with a new light and deeper introspection. Can you imagine the absolute world-shattering thoughts Luke must have had after Owen and Beru died?
Realising he was more deeply loved than he could have ever realised, even if Owen had a harder time showing it.
And Owen’s parental anxiety is shown in Kenobi! Owen Lars, one of the most dedicated fathers in the galaxy, probably died wondering if his son would ever know how much he really loved him.
Owen probably died with so, so many regrets. Owen probably died wondering if he deserved to raise Luke (which he DID) and if he had done enough to prepare his son for the world (HE DID).
Owen Lars has always been a heartbreaking character for me.