I saw a different version of this footage, consensus was they seem to have no thermal sights and were blazing away into Ukr trench/dugouts areas hoping to hit something. Spectacular but unsure if it did any good
The BTR-ZD does not have thermal sight, and the BMD2 does not either, except for the latest iteration the BMD2M. And that one does not look like a 2M.
But it is likely mostly done for suppression anyway.
The 2A42 has a variable rate of fire of either 200 rounds per minute or 550 rounds per minute. However, it can go up to 800 rounds per minute once the cannon is heated up by a few seconds of firing on full auto.
That high rate of fire is invaluable during engagements with concentrations of infantry, or when attacking a well-fortified position, and it makes the 2A42 a simply irreplaceable asset during engagements with stealthy adversaries.
Even with thermal imaging sights, hitting skilled, mobile and concealed infantry hiding in bushes is hard (simply because the concealement makes it harder to spot thermal signatures). Under such circumstances, the ability to saturate likely spots and areas of interest with high-explosive cannon shells is absolutely invaluable for infantry support.
Which, incidentally, was one of the reasons why the BMP-2 and BMD-2 were much more successful in Afghanistan and Chechnya than the BMP-1 and BMD-1.