Where did you see it on the list of the most corrupt countries? As per your original post:
"Argentina is nowhere on the list. Chile yes, Paraguay yes, Mexico yes,.... Argentina ???? No."
I do not find it hard to believe that Argentina did not make it to the top 30. There are 195 countries in the world. If you are ranked at #164 you can still be very corrupt without cracking the top 30 list.
Not sure why nobody made this clear yet, so let's try and straighten things out.
The OP put out a link to a Business Insider article which attempts to regurgitate the WEF report's findings. And in the smattering of countries they mentioned, Argentina does not appear. Which means nothing at all, except that the editors at Business Insider don't care about Argentina.
If you actually want to read the report - not drill down or anything like that, mind you, just read the numbers as reported - you need to
download the report, for starters. And because there is no table comparing the countries on the basis of corruption alone, you have to go to the country-by-country reports - those start on page 78 - and check line 1.14, "Incidence of Corruption".
You can only check one country at a time, and need to check manually who's ahead of who. UPDATE: It turned out to be trivial to copy/paste the data into a capable text editor*, then use some regex patterns** to cast aside everything we don't need, and separate everything properly with tabs. I've attached a tab-separated text file, ready to paste into Excel or Google Sheets.
At the top of the list are all the countries you'd expect. Uruguay and Chile are the highest Latin American countries on the list, with Uruguay tied with France for 23rd place and Chile one below at 25th.
Argentina is right in the middle of the list, tied at 73rd with Benin, Kuwait, and Swaziland (now eSwatini), and a bit ahead of Brazil, Colombia and Peru. Sounds about right.
Ecuador and Bolivia are just above 100, Mexico and Paraguay close to the bottom, and the existence of Yemen saves Venezuela from being dead last.
*BBEdit, in case you were wondering.
** That'd be:
find (\n[A-z .,'ô]+ \d{1,3}[a-z]{2} \/ 140\n)([\s\S]+?)(?=1\.14 Incidence of corruption 0-100) and remove group 2;
find (1\.15 Property rights[\S\s]+?)(?=\n[A-z .,'ô]+ \d{1,3}[a-z]{2} \/ 140\n) and replace with nothing;
find (\n[A-z .,'ô]+ )(\d{1,3}[a-z]{2} \/ 140)(\n)(1\.14 Incidence of corruption 0-100 \(best\) )(\d{1,3}\.\d )(\d{1,3}\.\d) (\d{1,3})( New Zealand\n) and keep only groups 1, 6, and 7, separated by tabs.