Yes, it is true; I worked on a Blazor Web Assembly project.

Blazor WebAssembly is slower than React/Vue in startup time

For heavy computations, Blazor WebAssembly can be faster than JavaScript frameworks

DOM manipulation in Blazor WebAssembly is slightly slower due to JS Interop

If you want a lightweight app with quick interactivity, React/Vue are better choices.

If you want to reuse C# code, have complex logic, or prefer .NET development, Blazor WebAssembly is great