Are adverbial modifiers in decline?

Words such as rather and quite are characteristically used in English to modify meaning,

According to Paul Baker in Lancaster University:

complex and understated forms of speech are in decline.

Guardian

He has said that he is rather fond of such “gradable adverbs”, stating that:

"Some words are starting to be drastically eroded from English – especially a grammatical class called “gradable adverbs” which consists of boosters (that emphasis another word or phrase, otherwise known as intensifying adverbs) like frightfully & awfully and downtoners (that reduce the force of another word or phrase) like quite and rather."

Guardian

On the other hand, Google ngram shows little ground for this concern in British English, either for the boosters or the downtoners. Here are the downtoners rather and quite:

And here are the boosters I mentioned:

My question to you is: what is your own experience of the claimed change in our language? And with which source does it agree – Professor Baker or ngram?