Nissan has been the General Motors (i.e. a manufacturer of mediocre cars) of Japan for a long time. Its low ranking doesn't surprise me. Likewise Volkswagen has been the GM of Germany for a while too. No surprise there either.
But Mercedes coming in 29/30? That surprises me. I've never owned a Mercedes but I thought they had a reputation for reliability.
I've owned two and my parents have also owned two. There appears to be a boom and bust cycle of reliability with them.
We still own one - a GLC300 from its first model year (2017) and it's basically been perfect. Zero problems beyond some cosmetic stuff w/ a seat rip but that's wear and tear. I care more about mechanical.
On the other hand, the E-class sedan we owned was nothing but trouble. I remember looking at some of the reported reliability data and it seemed like every 3-4 years, you'd have this cycle where the first year had great reliability and then it degraded over the next 2-3 years. When they released a new trim, reliability was back up.
Note - this is heavily anecdata, but having talked w/ other folks that owned multiple MB's, they felt it was similar.
My theory is it has something to do with the models manufactured in Germany versus the ones eventually offshore. Something doesn't translate as they offshore manufacture.
But Mercedes coming in 29/30? That surprises me. I've never owned a Mercedes but I thought they had a reputation for reliability.