For me, it’s “learn everything”.
The best devs in XYZ language/framework aren’t the ones who are experts in XYZ, but the ones who are just good enough in XYZ and 15 other things that they see what XYZ excels at, and lacks, and how patterns from elsewhere could be adapted to supercharge XYZ’s strengths and mitigate its weaknesses.
Why do we let execs sell stock received as compensation at all?