but have some physical metal rods as backup.

Do you know how high the animal can jump? Do you know whether or not they'll be able to climb those rods?

Also maybe don’t make the dinosaurs bulletproof.

How would you know which weapons an animal is vulnerable to before it's fully grown?

The problem is you don't actually know many the variables you're trying to make a solution for. You're assuming you would have thought of a lot of these things only after you've seen another solution fail. Hindsight is 20/20. But if you didn't have the benefit of hindsight how are you going to solve a problem involving lifeforms with an unknown level of intelligence, and an unknown resilience to weapons, and having unknown behaviours? You're only going to know you missed something after whatever you designed failed.

There's the part of the movie where Hammond is eating the melting ice cream saying "next time we'll do it better." That would be you because you're certain you can solve a problem that's not defined by empirical evidence (it doesn't exist because they're new animals) but based on assumptions about a new lifeform being similar to existing lifeforms we currently have in zoos, and think keeping animals we have familiarity with is easy (it isn't, animals in zoos actually do escape containment).

You're showing the hubris the story is warning against. Science depends on empirical evidence, and there wouldn't be any empirical evidence on the behaviour of new animals grown in a lab. And if you are completely ignorant of animal behaviour (because you think it's irrelevant) you're going to be very bad at building a zoo. But you're countering that by ignoring all of the knowledge we have about building a zoo (animal behaviour is important!) because there's hubris layered on top of hubris.