Is 32GB of RAM necessary for serious development work?

Yes, upgrade to 32GB. If you run multiple IDEs, Docker containers, and many Chrome tabs, 16GB will choke—Docker alone can eat 4–8GB, Chrome another 4–6GB, plus your IDE and database. 32GB gives you breathing room so your machine won’t fight you for memory. Don’t cheap out; RAM is the upgrade that makes your whole machine feel faster.