Russia absolutely made a rational decision.
A bad one, because their facts were wrong, but one based off calculations rather than rolling dice:
+ Russian Cold War-era (and refits of same) military materiel is reaching obsolescence and end of life. Russia can't afford to modernize its military at scale (hence the obsession with announcing prototype superweapons)
+ US and European ties are at a low point, as a consequence of the Trump presidency
+ US is focused on China as a peer threat
+ Germany is uniquely diplomatically vulnerable to gas energy pressure, but only until additional renewables come online, transmission infrastructure is upgraded, and efficiency measures implemented (see the Nord Stream bombing whodoneit https://en.m.wikipedia.org/wiki/2022_Nord_Stream_pipeline_sa... )
+ Remaining ex-Warsaw Pact / non-NATO countries are likely accede to NATO in the next few years (see https://en.m.wikipedia.org/wiki/Enlargement_of_NATO#Current_... )
... ergo, there was no better time to make the attempt than now. Everyone just assumed Putin wouldn't be stupid enough to try.
But that calculation looks very different without the energy vulnerability, as Russia understands the economic difference between themselves and Germany.