It’s a historical thing that people still falsely claim is true, bizarrely without trying it on the latest models. As you found, leading LLMs don’t have a problem with it anymore.
Depends how you define historical. If by historical you mean more than two days ago then, yeah, it's ancient history.
Some LLMs do better than others, but this still sometimes trips up even "frontier" non-reasoning models. People were showing this on this very forum with GPT-5 in the past couple days.
The question is, did these LLMs figured it out by themselves or has someone programmed a specific coroutine to address this „issue“, to make it look smarter than it is?
On a trillion dollar budget, you could just crawl the web for AI tests people came up with and solve them manually. We know it‘s a massively curated game. With that kind of money you can do a lot of things. You could feed every human on earth countless blueberries for starters.
Calling an algorithm to count letters in a word isn’t exactly worth the hype tho is it?
The point is, we tend to find new ways these LLMs can’t figure out the most basic shit about the world. Horses can count. Counting is in everything. If you read every text ever written and still can’t grasp counting you simply are not that smart.