[tmm]

It’s not for the next person. It’s to keep the stuff in the toilet, in the toilet, rather than as an aerosolized spray that gets spread about.[1][2]

I guess it doesn’t really matter if your toilet is in its own room, but at least most houses in the US have the toilet next to the sink (where your toothbrush is).

Put the seat down before you flush, because it’s more sanitary.

[1] https://microbiologysociety.org/news/society-news/does-putti...

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692156/

[mkl]

You're talking about the lid, not the seat. Also, some of that aerosolised spray stays airborne under the lid and is released when you open it [1].

[1] I think Mary Roach talked about this in this interview by Adam Savage, but don't remember exactly: https://www.youtube.com/watch?v=kfZ9RrxQ5NM