Actually the treatment of sentient droids in those movies is one of the sour points for me, rewatching it now. Somehow it's OK to just wipe a droid's memories, or dismantle it, when it's just as much a 'person' as any of the organic characters. Blah.
In Sci-Fi terms the Star Wars approach to AI is nonsensical. You have sentient droids that are treated as possesions/slaves/butlers but there's no AI except for the droids, no spaceships that fly themselves or superintelligent AI minds or anything. And the aforementioned lack of voice for some droids.
But in cinematic terms the R2D2/C3PO double-act does make for some funny exchanges, so I guess that's what they were going for. So its kindof tropes first, world-building afterwards as an afterthought.
The novelization of the first Star Wars movie alluded to controversies over "droid rights", but that was a theme that never developed as the series progressed.