I don't know the internals of USCIS system for adjudicators, but I suspect the evidence is attached to a case. If this is true, then uploading makes sense, as adjudicator won't have to click around to find info from past cases. They'll have it in front of them for N-400. Which makes it easier to treat as a standalone case and approve it. Also, if prior info is lost, here it is.
Of course people can decide what they're comfortable with.
To me, uploading few digital files was very low effort. I was lucky to get approved on spot without RFEs. But I also applied under 5 year rule. Lawyer discouraged me from uploading tax return transcripts, which I did. Was never asked for it during interview.
Sometimes you have to listen to your gut and do what's right for you. For example, before interview I spent good time revisiting all travel dates. My case was so straightforward and clean, that the only thing adjudicator could try to mess up is accuse me of lying in the interview on some silly technicality. Lawyer said these questions barely come up and it's not so important. Guess what, adjudicator tried playing that game of reading incorrect dates and getting me to confirm them. I corrected adjudicator stating correct travel dates. And she got visibly disappointed because couldn't catch me lying there