The first game that comes to mind for me is Civilizations 4. I’ve probably spent hundreds of hours playing but after getting used to 5 and 6 I have a really hard time going back. Going back and forth between 5 and 6 I need to rethink some strategies but with 4 I feel like I need to rethink everything. I don’t know if it’s because of the tech tree layout in combination with the civics system, things like unit stacking, or maybe just a bunch of little things but it takes me a while to readjust.
Warframe has gotten so much better since 2020. I highly recommend coming back for a bit just to do the new quests. All your stuff will still work great in the new content. In fact, it’ll work better now that other damage types are way more viable. No longer have to mod everything viral/slash/heat.
Played from 2020 to around the end of 2022, already did all of the rebalance stuff since Rebecca became design lead. I really cannot go back. I beat it. It’s done. Regardless of the new frames, etc – I’m out of that “cycle” now. I’m mastery rank L2 if I am remembering correctly. No matter how much content they release - they’ll never release enough of it for me to want to return. I conquered Warframe. Legendary 2 rank. Most people don’t even reach MR15 before they crash out. Once I had everything in the game, it was done for me. Permanently.
Man warframe is such an interesting game. I bounced off it twice. When it first released and then again in like '17, but not long ago I fell into it hard for 3 months. So much so it was my #1 played game for my steam recap lol.