Where a lot of roguelikes fail

I was oblivious to the roguelike genre until I was staying at my bestie's one night and saw her playing Slay The Spire. I then stayed up til 4am playing it on her switch, got STS and have played many MANY roguelike games since then looking for similar fun. Most of these games start off really strong. A lot of them have a unique mechanic they introduce. There's a set of cards and/or relics and/or enemies and you do a few playthroughs getting to know how the game works and figuring out how to win. During this time, you're contemplating strategies and making interesting decisions, not sure which option is going to end up better for you. But it takes only a few hours, maybe 2-5 and you basically have the game solved. It offers different characters with unique abilities or unique relics and unlocks more dice/cards/etc. This process is really fun, discovering new things and figuring out strategies, and making interesting decisions. But most games fall apart after the initial discovery…