How hard is it to fire someone

Unless they're relatively new, and whomever they're reporting to has had the minerals to refuse to sign off on their probation, the answer is it's possible, but will probably take ages.

That being said, if someone is literally not turning up (are they office based?) when they're supposed to, that might make it a bit more expedient. Is the person pulling sickies (6 uncerts in 3 years is the max), claiming they have COVID, burning up all their annual leave, or just shrugging when they're asked where they were yesterday?

oh the irony

I've seen it a handful of times. They were managed out. Given awful jobs and no promotion or increments. Almost all left eventually.

They can, but the discrimination laws still apply.

I worked in a company where an man maybe 15 years older than the rest of our team was hired. A few months in we determined it wasn't working out, but HR wanted a whole lot of actions from us so that when we eventually let him go, he couldn't say we did it due to his age.

Remember no company wants their name in the paper over something like this, so never think you have a free pass within the probation period.

I'm public sector and we get 4 uncerts (self certs) a year. That would 12 in 3 years. There are specific rules as to how you can take them though. I don't think there's many employees who don't use all 4 days each year.

There's a well known story about one employee in the company who took no sick days throughout his whole career. Close to retirement he went up to have a meeting with the head manager along with a union rep. They asked if there was anything they could do to acknowledge this. He was told 'no', and that "those days are there to be taken"!

I think that's different just killing time until the next bus arrives. Be that retirement or a new job.

How many of those are genuinely fixed term project, though. The engineer might be, they're probably building something specific. But the public arts and literacy needs are not going away at the end of N years.

That's not my experience. Almost all of my team and colleagues don't use all four days each year. Those who do use all four days each year tend to have significant underlying health issues.

The organizations staffed by people out to grab as much as possible - and willing to risk the education, welfare and health of Irish citizens in strike action to do so - are giving up free money?

Pull the other one.

Edit:

Just confirms my point, post #7 here https://www.boards.ie/discussion/comment/122545668/

It's just a bit silly to keep banging on with the tired old trope that tries to position public service staff as some kind of different race with different motivations to others. Don't most employees, public and private sector, want to "grab as much as possible"? Aren't all those calls for small government and reduced taxation 'willing to risk the education, welfare and health of of Irish citizens'? This kind of stereotyping is fairly lame.
Public servants aren't a different race. They're a broad church, with all kinds of different motivations. The main thing they have in common would be that if they really wanted to 'grab as much as possible', they'd be working elsewhere.
You've clearly no personal experience of sick leave practices within public service.

I'm not sure if you've heard of the concept of 'strikes' or 'industrial disputes', where staff withdraw their labour which generally result in withholding of services, whether that's flights abroad or call centre phone answering or indeed (in contradiction of your claim) plumbing services; https://www.thejournal.ie/construction-site-strike-august-2024-6471797-Aug2024/
You may also have missed the fact that the last couple of decades have largely been peaceful in terms of industrial disputes in the public sector.
If the best you have to rely on is 'everyone knows', the standard Liveline trope, you're not getting very far.
As for morals and motivation, wait till you find out about how many people work in both sectors, sometimes at the same time, and sometimes chopping and changing sectors as suits them. They're the same people

They don't because generally speaking those in the private sector have greater morals than the public. That's my point. Nurses for example are quite willing to let cancer patients suffer while they stand at the hospital entrance. Sickening.

If the private sector had the same morals as the public, we'd be facing food, fuel, clothing shortages every time there was a grievance against employers or the government.

Thanks for providing me with more examples of the continuity of supply we can depend on from private employees! Quite a world apart from the shambles, money grabbing government employees, quick to hold fellow - the most vulnerable citizens - as pawns against the Government.

https://www.irishtimes.com/news/health/cardiac-and-cancer-surgeries-cancelled-due-to-nurses-strike-1.3786012