If you look at the earlier designs - stub tail and before, they tended towards a curved blade that tapered from around the 5/8” mark but were pretty consistent in terms of blade length. Making the blade wider does not make the shave faster or slower - and I really don’t see that holding more lather would be a deciding factor. Certainly, the small blades of 4/8” were probably made for trimming rathe4 than full shaves but as to why there was a trend towards blades of 1” and more I can only assume was down to less edge maintenance and a longer life when used by barbers who would need to hone more often.
From personal experience I don’t notice a great deal of difference in the end result between 5/8” and 7/8” which is the range of my collection. A heavier near wedge may be seen as more appropriate for shaving a heavy beard with multiple days growth - but the reality is that a 5/8” is capable of doing the same.