Since about 2006 my voicemail message has been “for a faster response send me a text message.” When I started my business I added my business name and rerecorded the rest. If a client can’t send a text instead of call then I’m going to charge them more.
Nothing I do need to account for relativistic speeds or quantum mechanics so I could get by on Newtonian mechanics just fine. Most people could get by on Archimedes.