I don't think this article is fair. Lots of people are given the title of senior developer at their current company and they have no idea that they actually are not senior. You can pop open your Medium digest and see several articles every day by people who clearly think they're more senior than I think they are based on what they're writing. In the industry, there is no specific definition of who is senior and who's not.

One thing that I believe makes a senior developer is you do your dead-level best to fix what's broken, even if I believe it's broken because someone completely ignored my advice. I'm assuming from your tone you think you're a senior developer. If it took so long to even find these people you look down on so much, then firing them puts you back to square one. Part of being senior means you raise the level of the team and meet them where they are. Yes, it's galling when someone is supposed to be senior and you have to rescue them, but it's kinda your job. And it might be that one day you may need rescuing, and it would be really nice if the person deciding whether to rescue you was actually still there and you hadn't crapped all over them.

Also, there are lots of ways someone can be senior, and I wouldn't necessarily say that because they couldn't figure out how to set up a Typescript (Node?) backend in your environment that that is brand new to them that that means they weren't senior.

Consider that maybe you were a bit upset they were hired over your advice and at the least you weren't as supportive of their success as you could have been. I've had coworkers actively sabotage me when they were upset I was assigned to do work they had wanted to do. Not sayin you would do that, but the fact you're on here assassinating them is maybe not the positive you think it is.