For Loop to compile data from multiple dataframes with varied number of observations

Question

I have created a forloop that iterates over a list of dataframes and creates a dataframe output like the one below. However, each possible pair of users does not appear in each dataframe; users appearance varies from one iteration to the next. Some dataframes only have 10 pairs, while others have 200.

user1	user2	value
Scott	Clark	.067
David	Sarah	.234
David	Clark	.544
Thomas	Sarah	.324
Clark	Thomas	.761
Sarah	Clark	.921

I would like to compile a single dataframe to hold the results (i.e. value) of each iteration, so the first two columns are used as a matching reference, and the value column is added for each iteration, populating the cells with the values matching the two users. Each value column being identifiable by the date represented as i in each iteration (i = "2020"). However, some pairs of users may not have comparable data for a given iteration, in which case, I would like those cells to have NA. The resulting dataframe should look something like the one below.

user1	user2	value_2018	value_2019	value_2020	value_2021	value_2022
Scott	Clark	.067	.067	.098	.067	.098
David	Sarah	.234	NA	.777	.222	.756
David	Clark	.544	.567	.754	.121	.334
Thomas	Sarah	.324	.123	NA	NA	.443
Scott	Clark	.761	.234	.437	.878	.543
David	Sarah	.921	.345	.958	NA	.299

Any help would be greatly appreciated. Let me know if I am failing to include some important information.

Here is the dput info:

structure(list(user1 = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L), .Label = c("Bilirakis_Gus", "Boozman_John", "Brady_Kevin", 
"Buchanan_Vern", "Burgess_Michael", "Burr_Richard", "Carter_John", 
"Chabot_Steve", "Collins_Susan", "Cornyn_John", "Fortenberry_Jeff", 
"Foxx_Virginia", "Grassley_Charles", "Graves_Sam", "Jordan_Jim", 
"Latta_Robert", "Lummis_Cynthia", "McCarthy_Kevin", "McCaul_Michael", 
"McClintock_Tom", "McHenry_Patrick", "Murkowski_Lisa", "Portman_Robert", 
"Posey_Bill", "Rodgers_Cathy", "Rogers_Mike", "Thompson_Glenn", 
"Thune_John", "Toomey_Patrick", "Wicker_Roger", "Wilson_Joe"), class = "factor"), 
    user2 = structure(1:10, .Label = c("Boozman_John", "Brady_Kevin", 
    "Buchanan_Vern", "Burgess_Michael", "Burr_Richard", "Carter_John", 
    "Chabot_Steve", "Collins_Susan", "Cornyn_John", "Fortenberry_Jeff", 
    "Foxx_Virginia", "Grassley_Charles", "Graves_Sam", "Jordan_Jim", 
    "Latta_Robert", "Lummis_Cynthia", "McCarthy_Kevin", "McCaul_Michael", 
    "McClintock_Tom", "McHenry_Patrick", "Murkowski_Lisa", "Portman_Robert", 
    "Posey_Bill", "Rodgers_Cathy", "Rogers_Mike", "Thompson_Glenn", 
    "Thune_John", "Toomey_Patrick", "Wicker_Roger", "Wilson_Joe", 
    "Wittman_Robert"), class = "factor"), rhetsim = c(0.532304260552694, 
    0.565448793804611, 0.614746610378663, 0.41456827871494, 0.680331655545798, 
    0.402937226093047, 0.635434336603617, 0.703608799728453, 
    0.592589001800602, 0.561932070884369)), row.names = c(NA, 
10L), class = "data.frame")