Time is the only true resource we have. We all die. How much of someone's time should be wasted because you find someone better. There's 8 billion people on the planet and new ones born every day.

To only be valued until you find someone "better" is why reasonable societies have said to capital you can't fire people without cause

You call it cronyism which is not applicable to this situation. Or you need to explain how you are using that word. Because that's a term for when someone doesn't have the qualifications or other nominal requirements yet gets rewarded anyway.

In the situation we are discussing your argument is making asserting they can't do the job, when your arguing that new people might be more capable.

Age isn't the issue either. It's tenure at a job. It's unfair to throw someone out after they have been at one location for a long period of time. How cruel is it to force someone to start over after spending significant portions of their life there.

And your argument about merit ignores that we are fallable. There is no objective and definitive methodology of assessing someone's merit. You can come up with a system sure, but that doesn't mean it is perfect or even that great, but you can do it.

And what message does that tell your team? What does that do to moral. Bobs been here for 20 years, but new guy graduated first in his class yesterday so Bobs out cause he wasnt even top 10 in his class of 1000 people. That's rediculous too.

Theres no humanity in that decision only cruelty. Sure it sucks for the new guy to be let go, and they may be amazing, but Bob paid his dues.

And again this is about a situation where everyone would be kept if possible. It's not Bob sucks but he's in the union or we can't prove he's doing something wrong.

PS also keep in mind I am responding you saying seniority the DUMBEST methodology ever for choosing who to let go in a situation where it's deemed necessary to cut people. I'm not saying it's perfect or the best but its absolutely capitalist pig dog mentality to only consider who is going to make you the most money at any given moment.