the holocommunicators were ditched from a production POV because it was deemed confusing for viewers.
from an in-universe stand-point, it probably proved unworkable over time due to lag issues, even with warp 9.9999 boosted sub-space messages, or something.
from an in-universe stand-point, it probably proved unworkable over time due to lag issues, even with warp 9.9999 boosted sub-space messages, or something.