I think that's being way too charitable.
In a world where people are incarcerated on a scale unprecedented in all of human history, and where prosecutorial success is measured by number of scalps taken, the assumption that this is plain malice designed to let the state rob a few more individuals of their freedom makes much more sense than it all being just a big pile of incompetence and misunderstandings.
> As the global population grew 21 per cent, between 2000 and 2019, the number of prisoners worldwide jumped by more than 25 per cent, according to the UNODC data.
So, worldwide trend is upward.
> While Northern America, Sub-Saharan Africa and Eastern Europe have experienced a long-term decrease in imprisonment rates of up to 27 per cent, other regions and countries, such as Latin America, Australia and New Zealand, have seen up to 68 per cent growth over the last two decades, the study revealed.
So apparently your definition of “western countries” includes sub-Saharan Africa but excludes most of Europe and all of Australia and New Zealand?
Overall your own source supports their point and contradicts your own.
To be honest the text you are quoting doesn't talk about Western Europe at all, and I think if you exclude Western Europe, then "Northern America + Eastern Europe" is most of what remains of "western countries". Australia and New Zealand, while part of western countries, are so small that they are basically insignificant for statistics.
The data in the source[0], though, says the number of prisoners in Europe as a whole (as well as Northern America) has decreased (Figures 10, 12, and 13) confirming what GP said. Eastern Europe is quoted specifically because the decrease has been much more important (basically, the numbers are becoming similar to Western Europe).
There's no question that the trend in the West has been a decrease in incarceration rate, with Australia and New Zealand clear outliers.
[0]https://www.unodc.org/documents/data-and-analysis/statistics...