And luxembourg

Yes Luxembourg will be first, here is a good article about it: https://www.theguardian.com/world/2018/dec/05/luxembourg-to-...

It was already really cheap, but it was annoying to always have to buy a ticket, have coins in your pocket to do so or remember to recharge your card. As a luxembourgish citizen that uses buses and the tram in luxembourg city from time to time, especially the night shuttles back home after going out, so I'm really happy this will finally soon happen.

I also think it financially makes sense for the country, all public transport costs the country 1 billion but the fares only bring 30 million in, so covering those last 30 million by taxes is in my opinion a good idea. The ticket machines can now get abolished which will save costs too and the workers controlling tickets will be able to do other tasks like related to security instead of hunting down people that didn't pay their 2 euro ticket.

must be nice to live in a country that's not even have half the size of Washington state and has a smaller population than one county (King, to be specific, has more than two million if I remember) in it.

I truly do not see why that matters. For the most part, such things are just an excuse to avoid installing a public robust transportation system. Yes, the amount of people you have, size of area, and terrain makes different sorts of stresses on your system - which is why they need to be somewhat customized to an area.

Businesses do this all the time, and I don't see how it is too big of a hurdle to overcome.

Past a certain point the cost of new marginal capacity is hundreds of millions, or billions of dollars, or even tens of billions of dollars in new metro, bus rapid transit, etc. That’s money that could be invested in welfare, housing, healthcare, etc. And it has to come from somewhere. And this is before you consider that it takes a while to build such projects.

Guangzhou had to pull the plug on free transit during the 2010 Asian Games because queue times for the metro increased by half an hour just to get into the station, let alone board a train. What’s the use of a free train if you can’t board it?

FWIW, as a resident of King County, I would welcome "free" public transportation. The buses on all but the busiest roads are nearly empty most of the time, so as a taxpayer I'm already paying for their cost. If nothing else it might make sense to make rides free on the routes where there are hardly any riders today, since they aren't paying for themselves anyway.

What has that to do with the ability to make public transit free? Fewer people means less taxes too.