The analog line in on a PLAY:5 is looking for a line level input. Very few TVs have such an output, most people have to jury rig something from a headphone out, and then play with the output levels on the TV, and the input levels on the Sonos before getting a distortion free signal. Very unsatisfactory, and easily messed up by folks trying to adjust the volume on your TV in ways they think is ‘right’, rather than using the volume controls in the Sonos app.
A Sonos speaker designed for connection to a TV works more efficiently, by getting rid of that 75ms delay on an analog input, and allows expansion possibilities for surround sound. Connection to the TV is either through an optical connection (the Sonos Ray), or through ARC or eARC for the Sonos Beam or Sonos Arc. All of these soundbars can be set up immediately, or later, with surround speakers and subwoofers as desired. You may want to look at www.Sonos.com for additional reference.