This poor individual has never been in a lasting relationship.
If you can’t talk, in full, with your partner such that you somehow need small talk, that’s not a relationship, it’s a one night stand that happens to last for 3 months to a year.
As other people in this thread have said, it's usually more about the person than it is the topic. I'm happy to hear my wife talk about the weather tomorrow but if the guy behind me in line at the store does it I'm answering in grunts and annoyed expressions.
Sure, but it also has more depth than the guy at the checkout. It ties into the garden, the potential outdoor activities, possibly premade plans, possible seasonal house prep (stow the hoses, shut off the outside water, bleed the lines.). And all manor of things tied to your life together. Thus it’s not really small talk.