It's worth remembering that "the Weste" is a set of democracies, so there's domestic (internal) politics confounding things, primarily around the side not in power pointing out that the money sent to Ukraine could be spent on [whatever they pick to score political points]. I won't get into the weapons systems being sent being essentially 'obsolete', in the sense that the West has more modern, more capable systems, so a lot of what's being sent represents a savings on storage and eventual disposal. (whoops, looks like I just did - sorry)