Hmm. Less vs fewer is not a simple matter. I'd say we should be inclined to excuse alleged misuse in the spoken word but be a bit stricter with the written word.

The trouble with "less" and "fewer" is that they are both the opposites of "more." Two words on one side of the fence but only one on the other. I've plucked some examples of the use of "less" and "fewer" from the Grammarly website Here goes:

Rebecca has less than twenty dollars left in her checking account.

Rebecca has fewer than twenty dollars left.

Ethan has been at his job for less than five years.

I wish I could spend fewer hours on household chores and more on watching television.

Baby pandas weigh less than 200 grams at birth.

Fewer than eight percent of the world’s people have blue eyes.

I see you have eaten less than ten percent of your mashed potatoes.

On the face of it, it looks like a bit of rule-breaking is going on there in places - but Grammarly adjudges every one of those examples to be correct. Sometimes, either word may be permissible. English is a wonderfully zany language, more or less...