I don't just read reviews on books, but I read them on other products too. It's funny people will take the time to review a product, such as air filter, or coffee grinder, or even a tea infuser; and they don't take the time to review the books they read.
Amazon, Good Reads and other sites are great places to put down your thoughts on a book. Readers do read the reviews. And reviews help place books on Amazon's status list. You don't realize how important that is.
I review books when I read them, and yes I don't just write books, I read books. Some are ebooks, which are easy to store... (they take up no space in my tiny house!) and some are hard copy on paper.
I know life is fast paced, and we all have limited time... but take the time to review when you read.