I've observed the same behavior on AMD and Intel at $WORK. Our solution (ideal for us, reads happening roughly 1B times more often than writes) was to pessimize writes in favour of reads and add some per-thread state to prevent cache line sharing.

We also tossed in an A/B system, so reads aren't delayed even while writes are happening; they just get stale data (also fine for our purposes).

Rust has an interesting crate for this, arc-swap [1].

It's essentially just an atomic pointer that can be swapped out.

[1] https://docs.rs/arc-swap/latest/arc_swap/