It is a problem, but depending on what publications you read, how often it happens can vary.

The reason is that, like AMP, Apple News only supports a subset of HTML. It's up to the publishers to adhere to those limitations. Some choose not to make a special Apple version or change their main content to be Apple-friendly, so Apple News does what it can to show what it can.

It's not ideal, but it's better than being reliant on Google.

Also, if you see an article that doesn't look right, there's an option to report that article to Apple. One of the options is "Content missing."

The content is essentially the same in both places: they're both just aggregating content from news providers. So you go with the one that has a non-awful UX. Apple news also lets you access paywalled content through a single subscription (News+), which is nice if that's your thing.