What operating system are you using on your mobile device? iOS devices have accessibility feature which may meet your need.
I have an android phone.
Unfortunately, there is no text to speech option per se in the latest version of Acrobat DC. However, as a workaround, you can turn on 'TalkBack' in Accessibility settings on your device which can read the PDF to you. Please note that this may not work with all PDFs and is highly dependent on how the content is embedded in the PDF. Also, turning on Accessibility may change some gestures on your device(for e.g. double to open an application instead of single tap or double finger scroll instead of a single finger scroll). To turn on 'Read Out Aloud', go to your system 'Settings'. Tap on 'Accessibility', tap on 'TalkBack' and turn it on.
After 'TalkBack' has been turned 'on', you can double tap on the Acrobat DC application to launch it and then double tap on the file you want to open. Tap once on the centre of the page and the 'Read Out Aloud' will be activated which can read the PDF to you.
Hope this helps. Please let us know if this is not a viable option for you.
Acrobat DC Team