Anti multi-tool, here. Multi-tools by themselves give a false sense of security, and potentially lead to being stranded in the middle of nowhere without the one critical tool that you are missing. And, muti-tools are usually awkward to use, with low leverage and challenges in tight spaces. A single 5mm WERA hex-plus key is worlds better than the stunted equivalent in your standard multi-tool.

I think all riders should look at their bikes carefully, and make an inventory of the various nuts and bolts and then do an assessment of what could go wrong. And what is unlikely to go wrong, and is not worth the weight penalty.

So for example, I do not carry a chain-breaker, despite frequent long rides in areas without cell service, and only bears to keep me company. I have only broken a chain once in decades of riding, and it was my own damn fault. I knew that I'd partially mangled the chain on installation, and it failed shortly afterwards, fortunately in civilization.