How bakeries do a soft crust breads and making the same at home will result in a crisp crust?
In a commercial bakery Pain de mie would be baked in a sealed tin. I think it is a similar bread to the `Pullman loaf', which is baked in a special Pullman tin. (Easy to find a picture on the web.) This minimizes crust formation.

More generally, domestic ovens, particularly fan ovens, are designed to cook food in a dry environment. Low humidity means heat gets transferred quickly to the exterior of the food. This is good for roasting meat etc. For bread it means you are likely to get a thicker and darker crust than in a commercial bakery. You can try to counterbalance this by putting a tray of boiling water into the oven just before the loaf, or (more successful in my experience) using a preheated Dutch oven inside your oven.