The appeal of turn-based RPGs, in my opinion, has always been how they can prompt the player to formulate strategies that achieve the most efficient use of each turn. However, this hardly describes most of the turn-based RPGs that I have played which, are often just about finding the optimal strategy and repeating it in every battle. During a conversation, I made the realization that while some people find turn-based RPGs dull, they do enjoy turn-based strategy games and deck-building card games. This discovery made me realize that maybe the reason some people don't enjoy turn-based RPGs isn't that they're turn-based but rather because they don't have engaging battle systems or enemy encounters.
A battle system is the rules that govern combat, which encompasses every action a player can take during battle. An engaging battle system has enough complexity to give the player many choices to consider. This complexity is present in strategy and card games with the variety of options provided by units and cards. I have trouble playing older turn-based RPGs because the battle systems aren't complex enough to allow the player to make meaningful choices. Most actions in these RPGs don't serve any purpose other than inflicting damage, making the decision easy. This simplicity is why turn-based RPGs with a basic battle system opt for party-based battles rather than individual ones because having more choices to consider each turn breaks up the monotony of the combat. Modern turn-based RPGs aren't as lacking in battle system complexity as older ones, but I believe the player should have even more choices. Complex battle systems mean more tools for the player, but this is meaningless unless the battles themselves are challenging enough to accommodate the vast amount of strategies.
An enemy encounter is more akin to a chess problem; in other words, a challenge that tests the player's understanding of the game mechanics. Strategy and card games, especially when played against a person of comparable skill, provide a challenge turn-based RPGs rarely do. To highlight this point, I would like to examine my favorite turn-based RPG series of all-time—Pokémon. Pokémon is an interesting case because while its battle system has complexity, the single-player adventure hardly utilizes it. Something that would be mundane in battles with human opponents like switching is shocking in single-player because, typically, the computer opponents don't act intelligently. My most memorable enemy encounters in the Pokémon series occurred while playing Stadium Mode (Pokémon Stadium) or Battle Tower (Pokémon Crystal Version) because the computer opponents act with a specific strategy in mind. Forcing the player to change their tactics makes combat more engaging because players must consistently adapt.
Of course, I can't guarantee that these suggestions will make turn-based RPGs appeal to everyone who doesn't like them, but I think they will make these games more enjoyable for fans of the genre. It is also important to note that more engaging combat can become tedious if battles are too plentiful. Regardless, these suggestions are crucial for turn-based RPGs because there is a growing stigma that the genre is antiquated. Even popular RPG franchises like Final Fantasy have abandoned turn-based combat for real-time action. The turn-based RPG isn't going anywhere as popular franchises like Dragon Quest and Persona are still going strong but, it is sad to see the genre mostly relegated to lower-budget titles.