The internet is used all over the world so I don't think we should fault people for having imperfect English. Some people may not use it all that much in their day to day lives even if they were taught it when they were younger. If you see someone with imperfect English there's a valuable cultural exchange to be had as that means they likely don't belong to the anglosphere that dominates most of internet culture. Also we shouldn't mock people for making minor spelling or grammatical mistakes because those can happen all the time in casual online conversations and aren't any indicator of intelligence or English proficiency.