It really helps to think of altars as their own being, and just like “nobody puts baby in the corner,” you wouldn’t want to put your altar in a dark, forgotten place.
Place your altar anywhere you can see it often. Where attention goes, energy flows, and vice versa. If you don’t like the placement after a few days, you can always change it. For example, I’ve kept altars on coffee tables, in my car, and in my hotel rooms.
Not to mention, a lot of authentic spiritual work is about experimenting with what works for you. In my tradition, for instance, placing your altar facing east (facing the rising sun) is considered a beneficial spot. However, I find that experimenting with your own space first—before you go down intellectual rabbit holes—helps you get a baseline of your own setup. Then, you can add outside teachings on top of the firm foundation of knowing what works for you.
Lastly, altars do not have to be in fixed location. Taking them with you wherever you go or moving them around is just fine. I’ve created paper altars that are about the size of a regular notebook and I carry them with me in my handbag.