For most peoples uses, a 3.5mm (1/8") analog connection is just as good as a dual RCA analog connection.
Technically with RCA, there is no shared ground (negative) wire, where as the 3.5mm is a shared return/ground/negative (whatever) wire.
And with the (dual, right and left channel)positive, there is more (maybe very slightly?) signal separation with each channel using it's own RCA jack.
And with RCA, the jack itself is more robust, then a 3.5mm jack/port, from when you keep plugging and un-plugging the connection (professional audio equipment should be robust).
But for every use, by most of the population, a 3.5mm should be good enough.