I understand, the SQL transactions are particularly helpful in case of write queries i.e. when there are multiple concurrent transactions involving write queries, One will get the error on commit if the another transaction has already committed before it, resulting in the updated data that first transaction might not have. so that it doesn't blindly update the data and doesn't stay oblivious to the previous modification that another transaction has done.
I also understand the "atomicity" aspect of the databases, a set of operations will be atomic, when during execution, Either all has to be executed successfully or if any error occurs rollback it completely (strictly no hybrid state)
I am particularly confused about the use of transaction during Read queries, What are the use-cases where transactions while reading the data is useful. (ex: May be lock the row when during reading, nobody should be able to modify it. Not sure if it's really a possible use case).