The PS4 seems to be getting closer to saturation in the US as it's unable to beat the Switch despite two large (albeit multiplat with the XBO) releases. Tells us that an substantial amount of the people that want PS4s already have them. I'm not very surprised though, I think I wrote in an earlier NPD thread that the status quo has certainly shifted from the XBO occasionally beating the PS4 for #1, to now the PS4 occasionally beating the Switch for #1, and that does indeed appear to be the case.
The 3DS though. Ugh. I predicted that it would crash quickly in 2018, dammit!