What example can you give to illustrate that claim?

[& var1, var2](){
    /* ... */
}

when you meant to type

[&, var1, var2](){
    /* ... */
}

can lead to data races in multithreaded contexts, undefined behavior, and sporadic crashing.

I struggle to tell if you are serious.

I think you've never written multithreaded or async C++ code. Or anything particularly complex if you're unfamiliar with the issues that I'm bringing up.