There are two assertions that are often made, neither of which hold any validity.
Firstly: That there is only one 'correct' version of the English language - namely, British English. Fine of you're in Britain, but not so otherwise. There are at least 17 mainstream versions of English in use, all perfectly valid. Not just me saying that - I'm happy to defer to linguists such as Professor David Crystal - a foremost linguist and writer of more than 100 books. Here are a few of his many videos on 'Englishes':
David Crystal - World Englishes - Bing video
Full Circle & David Crystal: The Future of Englishes - Bing video
David Crystal - Will English Always Be the Global Language? - Bing video
This too 'Cambridge English':
Varieties of English | English Language Learning Tips | Cambridge English - Bing video
As to spelling and grammar, some American English words make more sense than British English. For example, 'pencilling' in Br. English gains a redundant 'l' on the end of 'pencil' . American English does not.
And why - when we combine 'beauty' and 'full' - does the word lose an 'l' at the end to become 'beautiful'?
In my view, to deride American English or any other version as not valid is not only out of step with linguists, it's rude and pompous. Australians have two colloquialisms which nicely describe those who exhibit such traits: 'Tall Poppies' and 'Roost Rulers'.
The population of the UK is around 66 million. An estimated 400 million people speak one or another version of English as a first language, another 600 million are estimated to speak it competently as a second language, and an estimated 1 billion other people have a working knowledge of English if only a smattering, so that's 2 billion in all. Hence, the 66 million of us who speak British English represents just 3.3% of the total. So anyone who thinks that we have any influence at all on how English continues to evolve is tilting at windmills. Like t or not, More people in the world write 'color' than colour, and 'center' than centre.
Unlike France, where he
Académie française (established in 1635 to act as the official authority on the usages, has impoverished rather than enriched the language by trying (but failing) to prevent the 'Anglicisation' of French, the British have always been content to allow the language to accept 'loan words' 'borrowed' from other languages including French.
Even between England and Scotland word usage differs. In England , if we ask someone if they've had the Covid-19 vaccine, we'd say 'have you had your jabs', or 'have you been jabbed?' In Scotland they say 'jags' or jagged'. In England we might say 'that's outside my responsibility or 'outside my area', in Scotland, instead of saying 'outside', they say 'without'.
I admit that there are 'Americanisms' that are creeping into use in England which I'm not keen on. In particular, in hotels and restaurants it's becoming commonplace to see 'Restroom', 'Bathroom' and 'Washroom' instead of 'toilet', 'Lavatory' or W.C. We don't go there for a wash, a bath or a rest - we need the toilet, the most common polite colloquial term for which in England tends to be 'the loo'.
Secondly: There is a view, (debunked almost two decades ago), that 'text speak' is making young people illiterate. Not so. It's a language in its own right and makes perfect sense to abbreviate words when texting and to leave letters out of words you need to know what letters to remove. A couple of videos:
David Crystal on Texting (S1E2 of It's Only a Theory) - Bing video
Text speak makes youngsters' spelling BETTER, David Crystal says | Daily Mail Online
I have three granddaughters - one aged 23 with a first class Hons degree in English, and twins aged 21 in their second year at Oxford. They all gained A star grades in English at 'O' and 'A' level. They text extensively using 'text speak'. If I took them to task for that, they'd laugh me off the face of the planet and rightly so. It's me - not they - who lacks literacy as despite having a smartphone for ten years, I've not acquired the language of 'text speak' because I send few texts. (Some abbreviations have been around in written English for a very long time - ASAP for example, and rather ironically, the rather stuffy 'RSVP' - an abbreviation of the French term '
répondez s'il vous plaît'.
Incidentally, one development of the use of computer databases of addresses is the dropping of apostrophes at the end of street names, such as St Jame's or St James's'. (Now St James'). Had they not been dropped, it could literally cost lives by creating delays in the emergency services locating place names in the database to despatch police officers, firefighters or paramedics.
Just my wordy take on things - I'm quite content if others don't concur.