The second highest voted thing is mildly misleading because left parties are a lot more fractured, especially in EU elections. The afd could have 11% while 9 left wing partirs have 9.8% and be the most voted party, but that would be a better result than we have now with it being the second most voted.
The results are bad, but 16% is at least nowhere nesr a majority. I'm honestly more concerned about the CDU moving closer to the afd and still ending up with 30%, seems almost like many people don't like the afd because they've been told afd bad, but still agree with much of their ideology.