Canada

Well said. I will just add that the major distinction as someone else pointed out is that the CRA handles all the taxes for provinces, not just federal, and also administers benefits, which make up a large portion of its funding and staff.

I was curious and looked up their report card for last year CRA 2022-23 departmental results, and I’m not sure where this article got some of its information, but it’s quite a bit off, and doesn’t mention published info (at least not in the non-paywalled section).

There is a good table that shows money spent and employees, as well as explanations for the major increase for last fiscal and the major upcoming decreases. TL;DR: major new benefits and changes require employees.

The increase in actual FTEs in 2022–23 is largely attributable to the administration of measures announced in the 2021 and 2022 federal budgets and economic statements as well as those associated with addressing the post-pandemic sustainability of CRA contact centres and the administration of the one-time top-up to the Canada Housing Benefit and the interim Canada Dental Benefit. Over the planning period, the reduction in FTEs from 50,195 in 2023–24 to 47,631 in 2024–25, is primarily as a result of a decrease or sunsetting of funding to implement and administer various measures announced in the federal budgets and economic statements as well as those associated with the COVID-19 pandemic.

To your last point on comparing the CRA to other taxation authorities, some months ago I went down a rabbit hole and I found something like this on the OECD website, but can’t seem to find it now, so I will just link the main page. It wasn’t a comparison between tax administrations per se, but it was a short summary of each country’s stats, how much money they bring in, spend, where they fit globally, employee counts, etc. You could then compare to others yourself. Very informative, and according to those stats, CRA was near the top IIRC.