Is the product "Out of Stock" or truly "Unavailable"?
Shopping at a brick & mortar store is a completely different experience when compared to the same on an online store.
A customer visiting a brick & mortar store usually knows what exactly he is looking for and expects to be able to leave the store having purchased the product. On the other hand, a customer in an online store knows that there is a time delay and he cannot expect the product right away at his doorstep! Depending on the shipping method, the ordered product might arrive in a couple of hours or several weeks. Someone might have saved your product in their cart or bookmarked your product page in order to purchase it later. And having those pages removed because they are out of stock leads to your customer assuming that the product is truly unavailable. This leads them to other online stores where they can find the product they are looking for. So why do you want to drive your customers away?
Also, every time you remove and add a product page, you are wasting quite a bit of time, effort & resources of your team for a simple repetitive task. And of course, there are the SEO factors which you need to take care of because removing an item from your store also means that it is completely gone from the Google's index and anybody who lands on that page will be greeted by a "page not found".