The droids didn’t randomly land in the planet Obi-Wan was in, and didn’t randomly land close to his home either. That’s all text for the original film. They knew Obi-Wan lived somewhere around there, R2 I think even knew exactly where. “Secret mission, what are you talking about?!” (as R2 heads in a particular direction). He also escapes at night and has a specific place he wants to get to, which curiously (obviously!) is closer to Obi-Wan’s home since he shows up.

Hopefully it becomes obvious that R2 programmed the pod to land there, near Obi-Wan. And Obi-Wan lived next to Luke on purpose. I really, really fail to see a coincidence. And I’ve tried.