My personal preference is to use the triple backtick as that's the most common way to set code blocks in Markdown outside of Stack Exchange. I find it much easier to use.
When I am editing someone else's post though, if it's a small piece of code, I just select it and click on the {}
button in the editor. The default behaviour of that button is to use 4 spaces.
If it's a large block of text that needs to be formatted as code, I find it much easier to just add triple backticks at the start and triple backticks at the end.
On a side note, fenced markdown for code blocks wasn't available on SE until it was released in 2019.
Another thing to note is that in the case of a very large text, especially logs, using 4 spaces might not be possible as it can cause the post to reach its character limit. Although, I have never encountered this issue myself.
In summary, I don't think we need a consensus. Just go with whatever you prefer until SE decides to stop supporting one of the methods.