Why is Ukraine struggling so much to beat Russia?

According to wikipedia, Russians are fighting in Ukraine with roughly 200.000 soldiers, while Ukraine have 209.000 armed forced + 100.000 paramilitary + 900.000 reserves = 1.200.000 soldiers.

On top of that, Ukraine have the home advantage, the will to fight to defend their country, and a massive influx of money, equipment and other utilities from allied nations. Meanwhile, Russia have received no help from allied nations (China, India, Pakistan, etc), and their economy has been crippled by sanctions.

And yet, it's been about a month's worth of fighting, with Ukraine suffering heavily, their economy in pieces, their people on the run, and there have been very few counter-attacks on Russian soil.

Why is Ukraine struggling so much despite having a much stronger army? I know Russia's army in total is stronger, but they're not fighting with their total army, so that is a bit irrelevant.

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