https://minecraft.wiki/w/Server.properties
The online-mode key controls whether players without a Minecraft account (i.e. paid for the game) can join. It looks like enforce-secure-profile has something to do with chat messages getting sent to Microsoft. The history section doesn't mention either of these ever getting removed.
online-mode will become important when the devs decide Minecraft has reached end of life and shut down the authentication servers. Players who have a copy of the game client will still be able to play together by connecting to a server with online-mode=false. online-mode=true serves the purpose of limiting players to those who coughed up money for an account, helping to protect the server from ne'er-do-wells.