Investment Complaints vs. Trade Complaints, by Respondent States

This chart from UNCTAD shows the top respondent states in investment disputes:

And this table from WorldTradeLaw.net shows the top respondent states in WTO disputes:

What, if anything, does this tell us about the trade and investment litigation worlds?

Does it tell us that the U.S. is the most protectionist country, whereas Argentina treats foreign investors the worst?

Does it tell us that the large size of the U.S./EU markets makes trade complaints worth bringing?

Does it tell us that ISDS litigation against Argentina/Venezuela is seen by foreign investors as most likely to convince arbitrators that there is government wrongdoing which requires compensation?

Or is it all just very complex and confusing, and doesn't necessarily tell us much of anything?