But they're not profitable. They've made a loss for five years in a row, requiring government subsidies to stay operating (because them going bankrupt would make big parts of the country grind to a halt). Ticket prices are so high that it's barely cheaper than driving, and as soon as you travel with two or more people it's cheaper to just own a car. (Or even rent one; I traveled to the other side of the country once for a concert, my own car was in the garage. Did the math, it was cheaper and more convenient (door-to-door) to rent a car, pay the surcharge for long distance, pay the €35 in fuel, etc than it was to buy return tickets for three people)
The answer (I think, I'm no economist / politician / etc) isn't unionising and demanding better treatment, because the limits of the capitalist system they operate in have been reached. The answer is to stop trying to make it profitable. Re-privatize it: trains and public transit are a huge and hugely important nationwide economic driver, an essential service that capitalism can't be trusted with because the owners will try and get as much money out of it as possible, the employees get overworked and exploited and will shut the system down (as is their right) out of protest, and the people will have to deal with the consequences.
Just in my small bubble, the train strikes led to people not going to the office, missing events, lunch orders that either had too much stock that had to be discarded or that were cancelled entirely, costing that company thousands in income, etc.
Don't get me wrong, I'm not anti-union. I'm anti-capitalist though.