When people make these kinds of vocabulary mistakes, I like to at least charitably assume that English is their second language, but I've seen my kid's teachers make these mistakes, too...
I would like to add my personal bugbear of 'less/fewer'. 'Fewer' is such a nice word, it feels so pleasant to say, it would be nice if it saw more use.
One that really gets me that most professional get wrong is jive/jibe.
The last time someone used “jive” when not in relation to music was George Jefferson and other Black folks up to the very early 80s (I am Black before the pearl clutching starts)