It depends, of course, on a lot of things ~ mostly the audience, and your repertoire.

If you sing traditional songs, or contemporary songs written on historical topics, and if the venue draws listers who are as interested in historical context as they are in music, by all means talk at length between songs.

On the other hand, if you sing mostly familiar songs, much less commentary is required. And if you perform your own originals, intros are entirely optional (although there is probably, for most, an inclination to talk too much rather than too little about your own creations).

I'm sure that I err on the side of not speaking enough. Most of my experience as a performer has been on the street, where the object is to continue making music uninterruptedly ~ most listeners are passing through, so those who would hear your spoken intro will be gone by the time you resume singing. The best bet for grabbing someone's attention so they'll stop and listen is to be making music, not speechifying.

I suppose I've let my old habits remain in place when I perform indoors on a stage (which is only an hour or two a month). I sometimes get a question or comment from the listeners after having finished a song, and so wind up doing more "out-tros" than intros.