Words with similar meanings can easily be used in the wrong context, which does not give a good impression of the writer and also doesn’t help to keep the specific meanings of words. Did you know that ‘fewer’ and ‘less’ are often used in the wrong way?

fewer: not as many items (i.e. relates to things you can count)
There are fewer tasks on my to do list now

less (or less than): not as much of something (i.e. relates to a collective noun)
Antibiotics resulted in less disease after WWII.