I could see email from a tablet but all texting through a tablet would be cumbersome. It depends on how much you use texting and whether you want to carry a tablet with you everywhere. I find a tablet a more portable replacement for a laptop rather than for a smartphone, personally
I'm currently doing just that. Texting is a pain but there are other benefits to a flip phone. I chose not to set up google email and contacts and use the phone only for calls and an occasional photo. I feel less vulnerable without having my entire life connected to my phone.
I can still use my old smart phone for everything except calling, or a tablet or my computer.