Scaling is not something intuitive to end user. Hard to say "pretty sure it scales" when your usage is so low scale, secondary effects are invisible to you
Of course sewers are amazing but they are used for a lot more than toilets. My point was: Composting toilets do not need to take up much more space than water-based toilets and it's entirely feasible to use them in many living settings. It's also possible to make use of the "waste" by composting it further, using urine as fertilizer and so on.
Scaling is not something intuitive to end user. Hard to say "pretty sure it scales" when your usage is so low scale, secondary effects are invisible to you