Affect on the binary size

From one of my projects:

$ cargo bloat --crates --release
 File  .text     Size Crate
 7.9%  18.8%   1.8MiB std
 6.4%  15.2%   1.4MiB zbus
 4.0%   9.4% 898.1KiB zvariant
 3.3%   7.9% 754.3KiB i3status_rs
 3.0%   7.0% 670.3KiB serde
 2.1%   5.0% 480.7KiB reqwest
 1.8%   4.3% 408.7KiB tokio

In this example, zbus + zvariant are responsible for almost 25% of .text section size.

I thought this issue can be used as a place to collect info and ideas on how to improve this.