That /users
route works perfectly fine for showing the top users (of all time).
For example to get the top 20 Mathematics users, use:
/2.2/users?pagesize=20&order=desc&sort=reputation&site=math
Which gives the same results as the top users page on math.stackexchange.com.
EG:
{
"items": [ {
"reputation": 431528,
"user_id": 12042,
"display_name": "Brian M. Scott"
}, {
"reputation": 429508,
"user_id": 6312,
"display_name": "André Nicolas"
},{
"reputation": 260417,
"user_id": 8508,
"display_name": "Robert Israel"
}, {
"reputation": 259414,
"user_id": 622,
"display_name": "Asaf Karagila"
},
... etc.