Meta given 30 days to cease using the name Threads by company that trademarked it 11 years ago

Yes you can, that is the definition of what a trademark is.

Could you imagine 20 different brands of Coke on the shelf?

The usage is specific to a market, however. For example, Delta Airlines and Delta Faucets. Both trademark "Delta."

According to Trademark law in many places you can.

Generally, you can only enforce your trademark (successfully) if the infringing group is in the same industry. So if I sold an educational service or toilet bowl cleaner called Apple the tech and music giant can't go after me for trademark infringement, though for music, computer tech and software they would have a case.

I agree, but tell that to Rockstar.

EDIT: I assume the downvoters aren’t familiar with Rockstar suing every indie game dev who released a game with “Monster” or “Monsters” in the title.