I keep seeing this sort of sentiment everywhere and I'm trying to understand it. The same thing happened after Charlie Kirk was killed and the arrest there hinged on a confession by the killer to his dad. A lot of commentary then that the police/FBI got lucky. Ditto Mangione. They got lucky he was found in a random McDonalds.

What exactly is the expectation here? Is there some sort of wide-spread belief that the world works like an episode of Law and Order and every crime is instantly solved by rolling up your sleeves and doing good old fashioned detective work?

Would assume for the majority of planned murder to be resolved as quickly as these highly publicized cases have been (the Kirk deal took about 2 days also) there's going to have to be an element of luck. Piecing together digital/forensic evidence is going to require time and effort. If it's not an obvious connection (domestic violence etc.) and there's no direct witnesses it seems logical you only have a few outcomes:

A) Going to be solved due to a lucky break

B) Going to be solved after a ton of time/interviews/piecing together forensic evidence

C) Not be solved.

Also he only "got away" because he killed himself. They likely would have caught him fairly soon after this because they had his identity from the car tags. I guess the point is though luck is all you have if it's solved this quickly because it's so random.

"this guy basically got away"

Titanic basically sailed safely across the Atlantic, except for a bit of bad luck.

But they found him? If he was alive, he probably would have been caught eventually, no?

Being smart doesn't guarantee you'll get away with murder: https://en.wikipedia.org/wiki/Leopold_and_Loeb

50% of murders are unsolved