The metrics of success are not defined in a measurable way with respect to the wiki projects; whatever they do result in won't be published until the end of the year. Maybe we will see 4.5 million worth of value. Maybe we will not.
I'm not saying that it's a waste in absolute terms: the initiatives are likely a net good to humanity. But I don't think they are going to improve Wikipedia very much when the money is withheld from the platform itself. Yes, that's a false dichotomy, because if you have enough cash, you can have both racial justice funds and engineering excellence. But somewhere a decision was made that one is more important than the other, and I suggest that if you can have only one, going the other way will help Wikipedia more.
And no, I don't have an example of an racial justice grant that resulted in a value, but I don't claim that they are axiomatically without it.
The WMF does do quite a few other grants that I think have been and are valuable in wiki-adjacent areas. A lot of Wikipedian in Residences are very interesting, and these can have vast potential for increasing access to non-Western cultural resources. Something that I'd say is more in the WMF wheelhouse.
[1] https://meta.wikimedia.org/wiki/Talk:Knowledge_Equity_Fund#W...