I've been watching videos all week of entire Russian platoons getting mowed down over open fields by MGs, hit by artillery attempting to ford that little river in the middle of the city, or near Adviika getting grenades drone-dropped on them while they were sleeping in the open. It's been a mess for Russia the last couple weeks with armor losses visually just short of 2000 tanks. Russian forces are still taking some ground in Bakhmut, but its being measured by singular buildings now and no major attempts at extending the encirclement. There's rumors that regular Russian units are filling the line because Wagner is spent. In the south near Zap, drones are guiding artillery strikes on C2 vehicles, SAMs, and radars 10km behind the line.
While yes, there is a large amount of material showing the Russians getting destroyed - we should not underestimate them. Not just "quantity has a quality all its own". English speaking media is likely to bias toward showing things favorable to Ukraine, and due to their much greater use of drones with cameras, there's just a lot more Ukrainian success caught on video and shared by Ukraine.
Now, regarding those T-54/55s:
purpose: Ukrainian target practice
Hard disagree. Sure, you absolutely wouldn't want to be in a T-55 in a tank-on-tank firefight with a more modern tank. However, that's a relatively rare scenario. The T-55 is going to be able to shrug off infantry small arms fire, grenades, etc as well as a lot (if not all) of what an older IFV or APC can do. Sure, it's vulnerable to ATGMs like Javelin or TOW, but so are the more modern Russian tanks. T-55 is going to be quite good at the other things tanks are called on to do, like shooting buildings being used as cover/concealment for enemy infantry, indirect fire support and such.
One major advantage of the T-55 is that it uses completely different ammo compared to more modern tanks (100mm rifled). Ammo shortages have been a real problem and T-55 won't be competing with any other Russian tanks for ammo. Ammo was still in development into the 1980s when a APFSDS tungsten carbide penetrator was introduced.
Another advantage is it's less likely to blow up/pop the turret if there is a penetration - something like a T-64 has powder in cardboard tubes. T-55 has it in a brass casing because it's a one-piece shell. The crew at least has a chance of getting out before it blows.
Oh, and Ukraine is using T-55 as well. I ended up doing a bit deeper of a dive on these than I originally intended, so here it is:
Slovenia donated 28 T-55S to Ukraine. Admittedly these are noticeably better than the versions of T54/55 Russia is pulling out of storage. It's a pretty thorough modernization (for the '80s-'90s anyway.) The "S" upgrades included a main gun upgrade (L7 105mm, produced by Britain) which is controlled by new digital ballistic computer driving new stabilized fire control system. With modern ammunition, it can can penetrate a T-72 - plus we have laser detection for smoke grenades, added ERA bricks and an upgraded engine. Modern ammunition is relatively plentiful with multiple active manufacturers. T-55S also has some optics upgrades, with both the gunner and commander having day/night sights (probably no thermal imaging, but that's unclear as Slovenia offered thermal imager upgrades when they were trying to sell them off in 2016) and a laser rangefinder for the gunner. Only the gunner can fire a Russian T-55, in T-55S either gunner or commander can aim and fire.