It's no different to speaking in a broad Geordie accent and dropping in aye and like every 10 seconds. There is no such thing as talking 'properly' in English with regards to general speech. That's why it is the global language. It's really no issue, unless you are required for a role where clearer speech is necessary and you should adjust accordingly. Some idiots on a Youtube channel do not need to so.
The real issue, rather than their dialect, is that they're an embarrassing pack of morons.