I haven't used all of them, but I have used both the 9 point and the 45 point types, and the difference is massive. The 45 point was far, far more tactile and responsive. I don't mean speed of autofocus, but the actual way that the points sit over top of the viewfinder and light up, it's hard to explain. I'm sure part of that is software, but owning an older model and then trying out a newer one in the camera store in like 2013 really was eye opening, it blew my mind. The 9 point feels like a toy.

On the other hand in actual usage i don't think that they are really that different. It's useful for sports/wildlife for focusing closest moving target (and speed of AF on these cameras was not that quick so you were hunting focus anyway). Otherwise selecting some offset autofocus point is pretty niche. With more static subjects majority of photographers would use the single middle point, focus and then recompose.

It's only with advent of smart focusing of mirrorless cameras with people/faces recognition where there is a big difference.

I started to write a stupid comment about how insanely fast the focus on the EOS R5 C is- only to remember it’s a non reflex !

The difference in focal time between my 5D mkii even with the best lenses, and the R5 C with a cine servo or vcm is insane. The R5 feels instant and only ever searches if it’s been locked to an inappropriate point.

For most stuff it's not a huge deal. Keep in mind however that for years the latest and greatest pro camera bodies were going to people getting photos at the Olympics and things like Formula 1.

Getting something or someone flying through the air at high and unpredictable speed perfectly in focus is pretty impressive