IMO 28 is the nest step. The gulf between 35 and 24 is quite natural for most purposes, but with street it has an effect not only on framing but how close you have to be and the dynamics of how you interact with an often mobile and sometimes sensitive subject. I this regard 35 and 24 are miles apart.
I think 28 is very different to 35 in terms of street use. It is substantially wider the dynamics are very different.
I dont't like 21 for street. Its too wide, leading to compositions that have a slightly forced look IMHO. 24 is much, much less obvious in this regard, 25 a hair better, but 28 is where thing start to look natural again, while still allowing for some really close interactions and dynamic framing. Gary Winogrand thought so too!
Not too long ago I went to do some street work overseas and toggled between 25 and 35. It was not long before I just wished I had brought nothing but my 28 Biogon!
As always, it is personal...