Are 2 litter boxes really necessary for 2 cats?

We have 1 cat and an automated litter box that we keep very clean (auto rotates after each use, deep clean it and fully change litter every 2 weeks). We’re considering getting a second cat, and debating the second litter box situation. We know numerous people with multiple cats who don’t have 1 box per cat. We also don’t have a wonderful spot for a second box, so in the end we may need to stick with one cat for now if it’s truly that important. Our current cat has never once had an accident outside of the box, so I don’t really expect a new cat to cause this to be too much of an issue for her, and I figure it could be something the new cat could adjust to alright. What do you think? Much appreciated!