At large timescales, yes. But not at timescales relevant for rapid security updates.
They get rebuilt when a change in the package is made, not when a change in a dependency is made — which is a huge difference.
There are plenty of packages that might not get an update for a long time (month, half year, … whatever their release cadence might be).
Dynamic linking makes it _easier_ to handle security, including checking if your program is linking to a broken library — static linking does not have the same means.
Statically linked programs don’t mean you know what is being run either, you can always dlopen() and all kind of shenanigans like Go and Rust do.
What is a security nightmare is statically linked binaries, you have no clue what they are linked against.
Debian did the strongest push for reproducible builds, and is 100% source available.