When I was just starting out and only doing this part time I would miss a lot of calls because I couldn't answer the phone while I was at work... I missed out on thousands of dollars worth of work simply because I couldn't answer the phone in time. Many customers who are just looking for basic detailing services like a wash and interior detail (or whatever) will just start calling down a list of providers, usually from an internet search, until they get one who can schedule them quickly.
Now, as my main source of income, I can not imagine NOT using one method of communication simply for my convenience or preference. I have clients who email, text, call, chat or just book online. I think, as a business, your goal should be to make it as convenient as possible for potential clients to get in touch with you. Otherwise you are just loosing money to your competition who will actually answer their phone/email/etc.
In general I will continue a conversation using whatever method the client chose to originally contact me. My assumption is that if they texted me then the probably prefer me to respond via text rather than call them back or shoot an email.