Because money spent in an efficient and effective system has more power than money spent in an ineffective and bloated system. One example - Germany doesn't actually have enough helicopters operational to meet their needs, so they used civilian contractor helicopters in Afghanistan.
The structures are just so different that it's hard to make good comparisons. Germany can't keep its troops and equipment equipped or repaired _at home_, while Russian is capable of doing so thousands of miles from beyond its borders.
The German military in particular is "neither structurally capable nor equipped" to meet its defense obligations, according to the German parliamentary commissionor for the armed forces. Their helicopter readiness is something like 15%, they don't have the funding to keep their navy seaworthy, for most of 2018-20 they only had enough operational armaments to keep 4 of their eurofighter jets armed. They don't have enough body armor for all their troops, so they rotate it out to whichever battalion is active. Current bundeswehr projections are that they'll be able to equip all their troops in 2031.
It's gotten so bad that the German 2019 readiness report was kept secret, after the 2018 report was so bad.
Long story short, the German military is fundamentally incapable of meeting its basic defensive goals (defending the home territory of the nation), while Russia is a near peer competitor with the United States, and is capable of offensive force projection thousands of miles from it's home territory
Links for the quotes and numbers.
https://dsm.forecastinternational.com/wordpress/2019/01/31/g...
https://sofrep.com/amp/specialoperations/germanys-military-r...
https://www.strifeblog.org/2020/07/03/the-german-military-mu...