The Real problem for Russians is Artillery shells and Tanks. They are loosing so much tanks. Perhaps 20 percent of all tanks are knock out already. They cant continue like this for a long time.
Artillery hunger is an issue for both side, the real reason why they're magnifying the Russian problem is because the common wisdom is Russian army is an artillery army, so shell hunger will affect them in a more drastic manner than Ukraine.
The problem is that this casualty ratio was achieved when Russia had much more firepower than Ukraine, and at the cost of lots of tanks, artillery pieces and ammunition. Russia had a huge fire rate of artillery shells that it cannot sustain long term, and they still managed to lose more men than Ukraine.
While Ukraine’s military gets quality improvements from NATO equipment donations, Russia‘s assets are dwindling and they are bringing older tanks and vehicles. Once they can no longer afford to shoot artillery like there is no tomorrow, their strength will be greatly diminished, and the casualties ratio will be much better for Ukraine.
The reports are fairly recent...from February and this has taken into account the mass Russian casualties from the chaotic Kyiv ,Kherson and Kharkiv campaign, as well as the months long human wave attack on Bakhmut. Also because its February that means the number speaks about Ukraine casualties even after receiving Western equipment like HIMARS, PzH 2000 etc.
By late April or May, Ukraine is expected to mount a huge thrust at one of the fronts, and that means that Ukraine casualties will skyrocket because offense does eat up casualties at higher rate than defence. Especially prepared defenses. If we look at Kherson campaign where the Ukraine army are bogged down by underequipped and undersupplied Russian garrison with only one working supply line to feed the entire front and we look at the planned scope of Ukraine thrust into Azov sea and Crimea, its very concerning to think of how high the casualty rate will jump for Ukraine even with qualitatively better equipped land equipment. I have explained for example, why Crimean geography will bleed any offensive a lot.
One more thing, the Russian air force are still very much intact, and F-16s aren't coming online anytime soon, their artillery is dwindling (so does Ukraine) but it just happens that their use of PGM has jumped quite significantly, and this is confirmed by Ukraine officials themselves. So its still 50/50 chance here for both sides. Because air power >>> artillery power.