Are Yiga programmed to snag weapons lying on the ground the way they are bananas? That's news to me. But I suppose they are supposed to be thieves, kinda?
Master Sword way too small for him, though.
I didn't know they could do that either. If you ask me, them being able to pick up any random object kind of undermines the whole Yigas-being-obsessed-with-bananas meme.
I think that being able to wield the Master Sword isn't so much a matter of worthiness, that's a little too subjective. Link, specifically in BotW, is shown to have almost a relationship with the Master Sword. He was lead there to draw it at a young age, and we see it tied into his own life force when he almost dies. Perhaps it's the spirit of Fi or the discretion of the goddesses at work but I think if anyone else were to try and use it it'd be just as powerful as any old kokiri sword. When the chosen hero uses it, or someone who has proven to the goddesses they can be that hero like in WW, it unlocks the power to seal the darkness and shoot lasers when the wielder is at full health.