Do the PhD for yourself-- for your satisfaction. Chances are that you'll get your PhD but you will still need to hustle outside academia to find a business partner. If you don't have a big desire to get a PhD then it's probably best to skip it and start to actively search for a co-founder now.

I am now doing a PhD, part-time, and have worked with with a lot of PhDs ("quants") in trading/finance as a desk dev, and have been a CTO and maybe about to become one again. All are good and interesting and have their pros and cons. And it's not either/or!