Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021

Use a comma between all items in a series
The comma
Punctuation

When three or more items are presented in a series, those items should be separated from one another with commas. Items in a series may be single words, phrases, or clauses.

Although some writers view the last comma in a series as optional, most experts advise using the comma because its omission can result in ambiguity or misreading.