That's not to say that no one should ever say anything to an stranger, it's just to point out that there are non-zero consequences to your actions.
I think that depending on who you talk to they'll give more or less consequence to making someone feel uncomfortable. (I'm not strictly talking about dating or talking to someone you are possibly romantically interested in). Some specific extreme examples are: at work or if you are in a position of power over someone (you are their boss or their teacher)- or these situations there are more consequences to having an interaction where someone felt uncomfortable.
Yes, those are cherry-picked relationships, but just to say that fear of making people uncomfortable is a real and valid concern. Is your discomfort made up in your head? Many times it is.
Back to OP, relationships are complicated... it's not hard to see why people end up talking to AI bots instead.
Fact is, the more you worry, the less success you'll have. Which reminds me of Hamlet -- the original worry-wart -- who said it best:
> 'conscience does make cowards of us all,'
From my view:
From your view: ...point is - doesn't matter if they're confused or surprised you spoke to them. there's an assumption that if you speak up you must be out to manipulate them (sell something, convert someone, beg, etc.) and when you prove youre not, you help normalize ambient conversation AND fix your own sense of isolation.