Cite resources and references appropriately in APA format.

How have transformer$-$based models, such as BERT and GPT$,$ transformed the field of natural language processing?

Discuss their key advantages over traditional NLP approaches and share examples of real$-$world applications where transformers have made a significant impact.

Additionally, explore any challenges or limitations you foresee for transformers in handling large$-$scale language tasks and how researchers are working to address them.