Thanks for the details. It looks like in France this is fundamentally different. We have the labor law which is the same for everyone. It says the basic thing

Thanks for the details. It looks like in France this is fundamentally different. We have the labor law which is the same for everyone. It says the basic things, but it is complete. If your sign a job contact, you can almost skip reading it because everything is codified and you cannot be screwed up. This also means that the negotiation is limited, even for salaries (the general rule is that you cannot be wildly different from a similar peer in terms of your benefits). Then we have collective agreements, which historically applied to a profession and were negotiated (sometimes very harshly) over the years. A company is part of a collective agreement and, on top of the labor law, applies better conditions from that agreement. The "profession" part is historical - my company, a high tech one, is part of the "metallurgy" collective agreement despite having nothing to do with metallurgy. But the metallurgy agreement is arguably the most favorable one (or one of the 2, 3 best ones) so great. Then we have unions, most of them are country-wide and a few specific to a company. They are bargaining with the company and form the core of the work council (this is France, do it is much more complicated than that :)). Unions call for company, profession or country wide strikes. Usually when it is the worst possible time for the population. We have an extreme love-hate relation with them. A strike (individual or group (the group one is 99.9% of the cases)) can (and does) impact the business, otherwise it would be quite useless. You cannot actively sabotage/vandalize your company (though it happens) but certainly do anything that hurts it: let it run unattended, block entrances, stop work and stop operations - the sky is the limit.