It’s already a thing with near-zero delay. MS Teams does it (dunno about the translation) and the QSMP Minecraft server has a bunch of livestreamers from different countries who use it for realtime translation.

[EDIT: Live demo from today. Shit’s impressive.]

What actually happens is that the current sentence gets “corrected” several times as you keep speaking. It’s a bit jittery and if the word order differs significantly then the translated sentence might be a bit wonky for a few seconds, and there are a few misses but overall it works really well; at least well enough that people who don’t speak each others’ language can have a conversation in their native tongues with essentially no more delay than reading speed. I can easily follow a livestream in a foreign language with the live subtitles (which was not the case a mere 6 months ago for any language other than English).