Bit perfect primarily concerns the OS audio stack between the audio player application and DAC, which does indeed have an audible and measurable effect on audio. See here:
http://archimago.blogspot.com/2015/11/measurements-windows-10-audio-stack.html
This is why many people prefer to use WASAPI/ASIO, and why many Android users use UAPP with an external DAC.
However, on operating systems with properly implemented audio stacks that either don't do resampling and/or have a much higher quality resampling algorithm such as Linux, iOS, and macOS, this is not a concern. On most Linux distros you will be getting "bit perfect" out of the box for most music since Pulseaudio tries to avoid resampling for 44.1 and 48khz and does not apply any weird filters to the audio like Windows does. Its default resampling algorithm is a little sub-par, but you can easily switch to a very high quality one in the config file.
iOS (and I think macOS) similarly tries to auto-switch sample rates based on what's playing and what the DAC supports, so no concerns there.
As far as the rest of the chain, as long as you don't have digital-to-digital conversion steps in between the source and DAC that may or may not be mucking things up (HDMI -> receiver -> optical, etc.) you shouldn't have issues if the OS audio stack is in order.