spread function in tidyr package

Why does spreading this tibble fail? How could you add a new
column to fix the problem?

people <- tribble(
 ~name, ~key, ~value,
 #-----------------|--------|------
 "Phillip Woods", "age", 45,
 "Phillip Woods", "height", 186,
 "Phillip Woods", "age", 50,
 "Jessica Cordero", "age", 37,
 "Jessica Cordero", "height", 156
)

pivot_wider is now preferred to spread. There were names with differing ages, so the snippet below distinguishes them.

suppressPackageStartupMessages({
  library(tidyr)
  library(dplyr)
})

people <- tibble::tribble(
  ~name, ~key, ~value,
  #-----------------|--------|------
  "Phillip Woods, Jr.", "age", 45,
  "Phillip Woods, Jr.", "height", 186,
  "Phillip Woods, Sr.", "age", 75,
  "Jessica Cordero", "age", 37,
  "Jessica Cordero", "height", 156
)

people %>%
  group_by(name) %>%
  pivot_wider(names_from = key, values_from = value)
#> # A tibble: 3 × 3
#> # Groups:   name [3]
#>   name                 age height
#>   <chr>              <dbl>  <dbl>
#> 1 Phillip Woods, Jr.    45    186
#> 2 Phillip Woods, Sr.    75     NA
#> 3 Jessica Cordero       37    156