Preventable with effort.
It might be a lot of effort, but that doesn't mean it's not possible.
What I actually think is that most parents severely underestimate the difficulty of parenting, so they half-ass it and then if everything works out OK anyway they tell themselves they did a good job. Outcomes are the easiest way to measure, but if they only succeeded by chance, then it really wasn't their doing.
If you're not willing to sanitize your household to make it child safe then you're not a good parent.
If you became a parent accidentally when you couldn't afford to make your household child safe, guess what? Also not a good parent.
I do have a good idea of how hard parenting is, that's one reason I chose not to do it. I've had several opportunities. I always passed, sometimes resulting in the end of a relationship. It was always the right call.