It's not about having spellcheck. It's about having the time to calmly read something over in a copy-editing mindset. Preferably with a different set of eyes than the ones that wrote it. Spellcheck won't catch brand-name errors unless GoPro is in your dictionary. It won't catch grammatical problems, or typos that happen to be real words.

The journalist who wrote it and the editor who approves it are probably way too distracted and have a ton on their plate. By the time it's going to press it all blurs together and errors slip through.