Yes. Inventory management is the resource you use to drive your profit and should take time to management it. Photographing a new product, creating a listing, and shipping the item has nothing to do with inventory management, they are required secondary tasks.
All bought inventory management programs are based on excel format. We looked at many different ones, and none of them had everything we wanted, so we just wrote our own. It is quite easy actually, because you only need to create the columns you want, and then write one line of formulas to do what you desire, Then, you copy the one line, 10,000+ times. Ours tracks 5 retail stores, and 5 online stores easily with over 100,000 sku’s. It does not matter if you enter a quantity of 5 in stock, in 3rd party software or on your own spread sheet, the 5 stays there until you change it.
Amazon inventory management gets it right 99.99% of the time, but Ghosting is a problem, and YOU cannot fix Amazon. You accept it as a part of Amazon business. We always have a copy separate from Amazon which we know matches what is in our building. Managing inventory is what allows you to see what is a good seller, what is a slow seller, when to reorder new stock, what to put on sale, etc. Cash flow is the life blood of any business, and managing your inventory is the heart that keeps the blood flowing.