For example, I couldn't see myself playing without https://mods.factorio.com/mod/factoryplanner for planning how many factories building Widget X and Widget Y I need to produce a full belt of Widget Y for my main bus..but once the planning is done I still have to build everything by hand just like any other player. It feels weird that I'm not getting the achievements just because the math was done in-game, rather than in an out-of-game spreadsheet.
I believe https://mods.factorio.com/mod/helmod achieves the same thing, and I'm sure there's many other UI-only mods that I'm unaware of that are still very helpful to other players.
As an option right now I can just download the standalone version of the game, and run two instances of Factorio, one standalone one with the mods to do the calculations, then a vanilla Steam one that I can alt-tab over into to play with the achievements intact..but it feels silly to have to do that.
