Is the slow creep of Americanisms into the British vernacular a pernicious assault on our linguistic heritage, or should we just chill?

Things mentioned in this podcast

Goncalves etc al (2018) on the Americanisation of English: https://arxiv.org/pdf/1707.00781.pdf

Britishisms in US English: https://www.bbc.co.uk/news/magazine-19929249

Differences in US and English Harry Potter editions: https://www.hp-lexicon.org/differences-changes-text/