Hi,
I think you are conflating a few things together. ACES is a colour encoding system and as such offers, various colour encodings built mostly on top of RGB colourspaces defined by a set of primaries, whitepoints and transfer functions.
The primaries chromaticity coordinates define the gamut (the triangle of colours) that can be encoded by a given RGB colourspace:
So when you are displaying an ACES2065-1 image on a sRGB display, you are only seeing the sRGB portion of the ACES2065-1 image, likewise on a DCI-P3 display you are only seeing the P3 part of the image. AFAIK, no consumer TV or Monitor is able to display BT.2020 entirely, laser projectors are almost there though. My understanding is that even though having super narrow-band primaries, the very nature of laser produces speckles that impose filtering which reduces the purity of emission. Don’t quote me on that though as I could be incorrect.
Cheers,
Thomas