FreeCiv has largely succeeded in making a "more fun" Civ2-like environment. They've backported some things from Civ4/5/6, like hex-maps, culture, and also changed some mechanics to better interact with these backported items (Democracy's "Deployed Troops" penalty now extends to your culture-zone, instead of cities/fortresses only, which makes sense).
FreeCiv in general suffers from outdated UI-choices. QT-client solves a lot of the issues though, and hopefully will evolve into something better.
FreeCiv got an incredible "solver" embedded into its engine, allowing you to optimally place your citizens. But the use of this solver-engine is arcane. Proper use of it leads to cascading advantages over your foes however, so its a must have to learn. (especially in auto-calculating rapture situations)
The use of optimal trade routes (with a good solver available in the FreeCiv-GTK client, but not in QT ... at least last time I checked) also is a major advantage to the players who use it.
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FreeCiv is likely a highly competitive, highly optimized game. But the community seems split and fractured. Some want to use FreeCiv-Web (and without the Governor / Trade route solvers, its a very different game), others like me prefer to play highly-optimal Civ2-like games.
FreeCiv's solvers (both the Governor solver, and the Trade Route solver) presents a difficult question to the community. Is the use of arcane constraint-solvers part of the metagame? If deployed for free so that everyone can use them, is that fair?
Its one additional step to learn before you can be an effective, competitive, FreeCiv player. But knowing that these lower-level items are "solved" by solver-systems makes it really, really difficult to go back to Civ5 / Civ6 (!!). So many times do I look at my citizens placement and realize that the AI-placement of citizens is terrible compared to the FreeCiv solver...
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The "core" of FreeCiv is pretty incredible. The solvers to make provably optimal choices (well, at least "locally optimal", such as most trade from a collection of 12-cities trade routes + auto-caravan decisions). As well as the use of "symmetrical island maps" to ensure everyone has equal starting-positions, and the first to deploy "concurrent turns" (long before Civ5 did).
It plays like a macro'd up / steroids version of Civ2 + minor mods as a result. The community needs to unify and decide if this version of the game is how it should be... and if so, rebalance the game in this field.
Well, basically, FreeCiv-web vs FreeCiv-GTK/QT flamewars in a nutshell.