Yeah, but Atletico Madrid's defense is one of the best in Europe. Plus Ramos does that in the CL as well.
I'd say they have one of the best busses in world football, but they're not that impressive on set pieces. Out of the goals AM have conceded in La Liga this season, 27% come from set pieces (not including penalties), they have scored 7 and conceded 6 from set pieces. RM, for example, are doing considerably better in this aspect, they concede only 7% of their goals from set pieces, they've scored 14 and conceded just 2. This is just La Liga, not CL. Source:
https://www.whoscored.com/Regions/206/Tournaments/4/Spain-La-Liga
It's not just Ramos dominating, but the whole team having a clear (and obviously very good) concept on what they do in free kick and corner kick situations.