I think this is part of a wider discussion, I don't want to derail things in this topic too much.
Basically I see three types of mobile devices/uses of devices:
- Phone - entirely touch driven
- This is what we are primarily focusing on here with this toolbar because this is the area in most need
- Tablet - Mostly touch driven with occasional keyboard support
- The needs on tablet are similar to mobile but currently proper tablet support is limited - something that is also being worked on as part of GSoC - Joplin Mobile Tablet Layout
- Mobile/tablet desktop, "pro" tablets - see Mobile app functionality improvements
So for this we are mostly concerned about phones and "normal" tablets where a keyboard isn't going to be used. This is mostly so that markdown syntax can be inserted into the editor without having to switch through a bunch of keyboard layouts or require the user to learn markdown syntax.