Dual Boot: New APFS Volume or Partition?

[Mity]

I want to have two different OS' on my SSD: my main one for personal stuff where I can keep my music and do my banking. And another one for learning coding where I can tinker and download things from the net without having to worry about malware.

I began going over tutorials and I came across two different methods:

Person A & B create a partition:

Person C creates a new volume:

I noticed that Apple recommends not partitioning:

https://support.apple.com/guide/disk-utility/partition-a-physical-disk-dskutl14027/mac

https://support.apple.com/en-us/HT208891

If I only create a new volume, will that keep my personal volume safe and free from malware if I get infected on the coding volume?

Which of the methods should I use?

Thanks