I think we’re on our own on this one… the dev team was quite clear about this issue. However it could have been turned into an optional thing in the settings.
In the mobile, the lack of this button is a nightmare: just a while ago, a big part of a post I wanted to quote in our forum that had an image on it took me almost a minute with several attempts since it’s not the easiest thing to select the text while scrolling down and with images in the middle (and this gets worse if you have an ad plugin too)… something that took me 1 second to do with the button. 
There’s this theme component:
Maybe someone with programming skills can adapt it.