Speaking from experience I'm going to state that sit bone width matters but only when combined with the appropriate saddle shape, which I feel is far more important than width.
What I mean by shape is the profile of the saddle when looking at it from above. Ie. is the saddle T-shaped or more triangular pear shaped. This brings us to the aforementioned angle of the pubic rami. In general women have a shallower angle and men have a steeper angle in the pubic rami. However there's so much variation between individuals that considering one's own gender in saddle choice isn't all that helpful.
The angle of the pubic rami dictates the profile of the saddle. If you're like me and have a really steep angle, you'll want something pretty triangular. If you have a shallow angled rami a more T-shaped saddle may work better.
This is where the sitbone width comes in to play. Ideally a saddle, even on a road bike, will accomodate a variety of riding positions and pelvic angles. This also includes a resting position where you're sitting up and having your weight on your sitbones or rather ischial tuberosities. However that position doesn't need to be perfect. The sitbones don't need to be perfectly supported, because we're typically not using said resting position for very long. It's mainly used to stretch a little and take a breather etc. Also I've found that a saddle that can perfectly accomodate the iscial tuberosities is often too wide for more aggressive positions as the back of the saddle begins blocking the inner thighs. A saddle that can perfectly support the ischial tuberosities is typically around 4cm wider than the measured sitbone width.
Riding style and style of bike matter too. For my sport bikes (road bike, tourer, mtb) I use a Selle SMP Pro as all of those are used with moderate to significant forward lean. With my utility bike (Tern GSD) the riding position is bolt upright and for that I use a saddle that does perfectly accomodate the ischial tuberosities. Funnily enough that saddle too needs to be triangular as even with an bolt upright riding position saddle shape matters. For the Tern I use a Selle SMP e-TRK.
The foot ankle analogy in my opinion doesn't work at all. I can't even think of an alternative since the dynamics are so different.