Also they get to chose which Charity gets it, so it can be a trade of favors between their upper management and the upper management or board members of the chosen Charity, favors which in due time will be repaid.

Further, in some Legal Jurisdictions the criteria to be a charity are incredibly low - for example rich Brits often use "charitable foundations" registered in the Channel Islands that pay all their expenses as a way to evade all tax in Britain, whilst at least some years ago the method used by the owner of IKEA to evade taxes in Sweden involved a convoluted ownership structure that ended up paying IKEA's dividends to a Charity "for the progress of interior decoration" registered in Luxembourg which paid all his expenses.

Or to put it in simpler terms: if company upper management are mainly crooks in the way they choose to treat customers nowadays (a.k.a. enshittification), it makes sense they would also be crooks when it comes to charitable donations paid by customers which go via their companies.