Is global variables good?

Hello, so.. i use global variables for all the player's data, with a dictionary:

_G.data = {}

game.Players.PlayerAdded:Connect(function(player)
   _G.data[player.userId] = UserData:GetAsync(tostring(player.userId)) or 
   {
       money = 0, lvl = 0, xp = 0, stage = 1
   }

end)

everything is in this global variable, but i want to know if it's good to use or sometime it'll break. and if it does break sometimes, should i use Bindable Events to call the data?

something like

in main:

data = {}

game.Players.PlayerAdded:Connect(function(player)]
   data[player.userId] = UserData:GetAsync(tostring(player.userId)) or 
   {
       money = 0, lvl = 0, xp = 0, stage = 1
   }

end)

events:WaitForChild("getData").OnServerInvoke = function(player)
return data[player.userId]
end

in some script:

local data = events:WaitForChild("getData").InvokeServer(player)

...