I think the contrast between accompanied and unaccompanied singing can be used to the singer's advantage - something you wouldn't get if you stuck exclusively to one or the other.

There are a small number of songs I sing that I prefer to sing unaccompanied, because I feel that the lyrics deserve to be heard unaccompanied, and an accompaniment would be a distraction; or because I find that some songs somehow don't lend themselves to any other arrangement (I probably could come up with an accompanied arrangement for them, but I don't think it would be as good in these cases).

I think if you occasionally perform an unaccompanied song in a set of otherwise accompanied songs, it can have more impact, as it makes the audience sit up and listen.

I know myself that I sometimes find myself so engrossed in watching (say) the musician's fingering and realise I haven't been paying any attention to the lyrics, which I regret sometimes.

Does anyone else do this?