Well, Ukraine can only do that if and when Russia culminated from the attack, right now, it still not and it's on going, if so, no point actually to even start doing prep work for any counter attack, right now is a "manpower" extensive phase, both side are chucking body into the pile. And both side seems okay doing so, which mean putting any effort other than this is probably just going to waste, may as well save them for actual push they know it is coming.
On the other hand, if you ask why both sides seems okay to put body into the pile, for Russia, that;s more or less what they can do right now, their attack is resort to WW1 trench storming tactics, drop a ton of arty into an area, then rush infantry in and storm that area, then rush more infantry in to take control, and then repeat the attack, that is going to cost them a lot of boots. Ukraine, on the other hand, I have no idea why they are okay with putting body into the pile. Yes, those are TDF guy, less well trained, more expendable, but still you are playing into Russian game, which they really shouldn't and if it was me, I would most likely abandon Bakhmut and move into a more defensible position now. Let them come to you and trade time with space, the Russian are making slow or very slow progress, that make trading space for time more favourable.