As the sibling comment says, you can always turn it back on when you want to do debugging. Personally, I mainly do printf debugging so I don't miss it much. Also there is the option of only turning it off for dependencies like:

    [profile.dev.package."*"]
    debug = false

I haven't tested how big the impact of that is, but it should be pretty large for projects with a larger number of dependencies.

Edit: I've tested it now on cargo-udeps [1], which has a large crate graph but only little code of its own and there is only a small difference between turning off debuginfo for all crates vs only for dependencies, but a sizeable improvement over compiling in debuginfo of dependencies.

[1]: https://gist.github.com/est31/1bb6e7d6f4be2a23701b8c7c1c678b...