Honestly.
The children learn to read through all sorts of classroom activities. Reading aloud to an adult is only one small part of it, and one which can perfectly well be done by anyone who can read. So if you hear your child read every day, don't worry if he doesn't read to the teacher very often- he will be having lessons in all aspects of reading which he then practices at home with you, and in some schools on parent helpers, other volunteers, year 6s- anyone who will sit don with them for 5 minutes.
The teacher meanwhile is doing loads of other things- things which you need to be a trained teacher to do!