As one data point, people never discus before-tax salaries in my home country (Croatia), it's always after-taxes and all other mandatory deductions. I believe the same holds true for at least several other EU countries from the region.
by "people never discuss" you mean the negotiation between the employee and employer is based on after tax salary, or do you mean casual conversations with friends? I haven't seen discussing after tax salary at all during interviewing process in the 4 countries I applied for jobs and got offers (Slovakia, Czechia, Switzerland, Denmark).
Officially, on the employment contract, the salary is shown before-tax, but after mandatory pension and healthcare deductions.
However, in the negotiations, in casual conversation, and when you're hearing someone talking about their salary in the media, it's always discussed after taxes. Most people have no idea how much tax (or health insurance) they're actually paying.
In Finland, I usually hear people talk about salaries before taxes and less often after taxes. For example my union has a yearly salary survey and publish results in before taxes salaries. But since it's so confusing, you usually see "brutto" ("gross", before taxes) and "netto" ("net", after taxes) being discussed when talking about salaries.
