> What we should have instead is syntax-aware diffs that can ignore meaningless changes like curly braces moving into another line or lines getting wrapped for reasons.

These diffs already exist (at least for some languages) but aren't yet integrated into the standard tools. For example, if you want a command line tool, you can use https://github.com/Wilfred/difftastic or if you are interested in a VS Code extension / GitHub App instead, you can give https://semanticdiff.com a try.