If you use Russian recruitment and army size numbers, you get much more realistic figures https://www.youtube.com/watch?v=Ja6-espHVSE. Russia is up to ~700k to 800k casualties Russia has lost ~3-4x more people than Ukraine so far.
It's sort of like how Western press has been claiming for over a year that 20,000 people have perished in Gaza, and the figure never goes up.
In this particular case Russia doesn't seem to care care about lives and uses WW1 style of waves of meat, which of course drastically increases losses