The framing around Ukraine aid is very much being shaped by Russian messaging. Much like Iraq Wars I and II, the stocks are already there, they expire, and they need replenishment so the argument isn't "let's give Ukraine a new car" the argument is "let's give Ukraine our old car and buy us a new car."

As far as "limited strategic value" Ukraine and Belarus have been the plains to thunder across in search of plunder since the Parthians. The Russians want it because it's a buffer state between Moscow and Frankfurt; Europe wants it because it's a buffer state between Moscow and Frankfurt. Arguing Ukraine isn't strategic is like arguing the Rhein valley isn't strategic.

And China isn't supporting Russia. China is not embargoing Russia but the bulk of Chinese commerce with Russia is commercial (see: embargoes) because so many Western companies have pulled out of Russia. Russia's biggest military partners at this point are Iran and North Korea, heavily-embargoed pariah states themselves.

I think there's a lot of fuzzy-headed thinking around "because Ukraine, therefore Taiwan" because it furthers the useful paranoia of pundits. This graph may be useful to your interests - American/Chinese trade has absolutely plummeted since the pandemic.