Why aren't the Ukrainians attacking more?
The blowing of the dam flooded about 60 miles of Russia's front. Giving Russia 60 less miles of front to defend. Allowing those troops to be concentrated to the East, in eastern Zaporizhzhia.
But if the Ukrainians wait a few weeks, as they appear to be doing, the flood waters will come down. Than the hot Ukrainian summer sun will dry out the wet soil. And a river crossing of that 60 mile stretch will be possible, forcing the Russians to send back the troops to defend that stretch, to prevent the "Land Bridge" to Crimea from being cut.
In addition, the reservoir that extended something like 120 miles upstream of the dam is now largely gone. When this land dries out, it will now be vulnerable, to a river crossing by an army. Something that could not have been done while the dam still stood.
So, in the long run, the Russians have just needlessly given themselves an extra 120 miles of frontage to defend. And gotten a lot of their soldiers sick with Cholera. Just to give them a temporary advantage of 60 miles less of frontage to defend. Something that the Ukrainians can easily negate by waiting a few weeks. They can delay the offensive. It probably won't take 4 months to advance 50 miles at a weak spot that they choose.
So blowing the dam gives the Russian's a temporary advantage of 60 miles less of line that has to be manned. But in the long run, just a few weeks from now, they will have to defend those 60 miles again. And up to another 120 miles on top of that. Giving them a long flank of 300 miles long, but only 50 miles wide, to defend. An attack that breaks through anywhere and advances a mere 50 or so miles, will break the "Land Bridge" to Crimea, likely resulting in the fall of Crimea. Which may cause the Russian people to throw in the towel and give up on this clown show. We shall see.