I don't think it's the single technical things. I agree when you're at the cutting edge, even 1 mistake is going to affect you, and every F1 team has to get things pretty much perfect to be on the podium.
But what is striking is the dysfunction is showing at Ferrari, and that's it's more than just 1 thing which is why they're way down at the bottom.
The most telling indicator for me was completely blown strategy and radio Vettel in that recent race and not even knowing if they are going to stretch the stint or not and asking him what he thinks without knowing; shows they are just coasting and not having these things thought out, and completely not in sync. Where it's expected to be top tier, you'd have supercomputers already simulating 10 different strategy scenarios out, and know exactly what to do. When the departments and stakeholders aren't even working well together, there is no way you're going to make improvements and keep up with the competitors that are a well-oiled machine, let alone even avoid mistakes with the platform you have.
When redbull made their call to pit max losing the win, as did mercedes not calling in Lewis but still squeaking it out, each team did it with a calculating the risks and probabilities and best expected value for points/win and knowing there's always a probability it goes a different way; they weren't just winging it.