Whatever is advertised its the business of communication, therefore standard English is required.
I hate hearing Scottish accent on fictional programs inevitably they are exaggerated and slowed down to the point nobody actually talks like that.
Having a very thick accent does hold people back in life, like it or not. If the boss man struggles to understand you, you can guarantee he isn't going to promote you into a position where customers and clients struggle as that could loose business.
Recently I heard DH on a call to a French company, OMG 😲I couldn't believe how amazing this ladies English was. I can barely buy a loaf in French nevermind conduct a business meeting and talk about legal clauses in a contract.
Modern languages is where we should be focusing our efforts not in trying to make us sounds like Rab C Nisbet.