That bridgehead seems to have a lot more staying power than I expected. I figured that as soon as it became a nuisance, Moscow would send a BTG, and the Ukrainians would withdraw.
I think I was a bit more hopeful, given the unmitigated success of the precursor when it came to the larger goal of degrading the Russian military. Even if they failed to secure enough territory to secure a defensible crossing point, which was reasonably likely, so long as Russian assaults need to get through the artillery cover from the other side of the river, the Russians were going to take very heavy casualties. At that point, it's not a major strategic win, perhaps, but it's definitely a major tactical win.
I was hopeful, too, that Ukraine would manage to secure the bridgehead they needed for a big territory sweep that would cut up Russian logistics and liberate a bunch of territory, but a bit guarded. Russia, of course, was put in a position where they can't really ignore the very real strategic threat that the Ukrainians created. That area is probably the least defensible for the Russians and Russia losing it would likely be a bit catastrophic for their situation as a whole. Russia may be dumb in a bunch of ways, but there was no way that that went unrecognized. Even if it was originally a Ukrainian feint or distraction, it would definitely get out of hand if they didn't respond. So, whether they wanted to or not, they had to strain their logistics even more and fight, however disadvantageous their position. All that hubbub about Ukraine potentially establishing a defensible bridgehead likely increased the pressure to respond, for that matter.
In short, it's pretty much a win-win for Ukraine, once they established control (not an easy task, that). Either they're able to inflict nasty and disproportionate damage on the Russians with the help of artillery that they couldn't really shift to other fronts anyways, advancing their overall strategy of degrading the Russian military or they're able to retake territory, with all the positives that that entails. The latter is, of course, what we'd prefer to see, but the former is also useful.