Perhaps the safety is the tradeoff with the comparative ease of using the language compared to Rust, but I’d love the best of both worlds if it were possible
Python and Ruby are two very popular counterexamples.
In both cases, while it wasn't curly brackets that drove their adoption, it was unavoidable frameworks.
Most people only use Ruby when they have Rails projects, and what made Python originally interesting was Zope CMS.
And nowadays AI/ML frameworks, that are actually written in C, C++ and Fortran, making Python relevant because scientists decided on picking Python for their library bindings, it could have been Tcl just as well, as choices go.
So yeah, maybe not always curly brackets, but definitly something that makes it unavoidable, sadly Modula-2 lacked that, an OS vendor pushing it no matter what, FAANG style.