Americans use more commas than the British*.
You often find long, asthmatic, comma-packed sentences in American newspapers. They don’t make for easy reading.
I prefer using plenty of full stops — periods to Americans — and sparing the comma. I only use commas where they aid understanding. Writers often underrate the comma’s use as an aid to sense.
Keeping track of who does what to whom is hard in long, comma-laden sentences. Breaking sentences into smaller units of meaning makes writing easier to follow.
Some Americans put commas between all clauses and sub-clauses. British-trained writers avoid them between short clauses at the start of sentences.
Americans use commas before and at the end of a sequence of items. This is sometimes called the Oxford comma. In Britain the last comma only gets used when one of the sequence items includes an and.
Some experts report American writers are slowly moving towards British patterns and commas are now less common on both sides of the Atlantic.
When training younger journalists, I used to joke about Americans using lots more commas than the Brits because they are so much richer and can afford the extra ink.
*Australians and New Zealanders follow the British comma pattern.