Andreas Kling mentioned many times they would prefer a safer language, specifically for their js runtime garbage collector. But since the team were already comfortable with cpp that was the choice, but they were open and active seeking alternatives.

The problem was strictly how cpp is perceived as an unsafe language, and this problem rust does solve! Not being sarcastic, this truly looks like a mature take. Like, we don't know if moving to rust would improve quality or prevent vulnerabilities, here's our best effort to find out and ignore if the claim has merits for now. If the claim maintains, well, you're better prepared, if it doesn't, but the code holds similar qualities...what is the downside?