That's a good GPU you got. I have an EVGA GTX 1070 SC overclocked to 1888Mhz and a quad core i7 6700k 4.2Ghz processor.
What sort of CPU do you use? For better results, you'll need a 3.4Ghz or faster, quad core i7 processor, at least. Especially with this game. I've built a sandbox map with 6k guests, 22 rides, and moderate scenery throughout, and manage 24-40fps. I play on 1920x1080 Ultra preset (full screen, not windowed).
Planet Coaster is not one of those COD or BattleField games where you can realistically expect 100fps or 60fps on 4k. Planet Coaster is a very creative game. It has very good graphics. Even big Youtubers run into lag when they build these huge detailed parks. And they have good systems too.
25-40fps is still playable. You can't expect butter smooth graphics with this game. And Planet Coaster isn't one of those games which you can play easily in 4k. 1080p still looks good and is still widely adopted. It has like a lot of computational stuff in it. Buildings which you can build piece by piece, and after a short time, you have over 3,000 pieces of objects. I think in Koali Beach, a sandbox map made by a very popular Youtuber, has over 128,000 object pieces in it. The AI guests in the game if you read their comments, you'll find how creative many of the comments are. It's not like it's been programmed into the game like a very short script.
The system requirements for this game are quite high. If you want to play on the higher settings, you should have a system which meets all of the "recommended" system requirements:
Recommended:
•OS: Windows 7 (SP1+)/8.1/10 64bit
•Processor: Intel i7-4770 or AMD FX-8350
•Memory: 12GB RAM
•Graphics: Nvidia GTX 980 (4GB) or AMD R9 380 (4GB) (Direct X 11 functionality required)
•Network: Any modern internet connection (for activation on Steam and the Steam Workshop)
•Hard Drive: 10 GB available space
The minimum requirements are a bit lenient, you can find it here:
https://support.frontier.co.uk/kb/faq.php?id=292 . But that only means you can play this game on like the lowest graphics settings. An i7 6700k and 7700k processor can be overclocked to near 7Ghz. Some people have actually tried that. Simulation games also tend to be very CPU demanding. Especially with Planet Coaster.
Maybe re-check the information you read and the source of it. If they offered everything for free, they wouldn't be able to support this game. And when it comes to how well game developers mix with their community, I'd say Frontier is the best. Not EA who charge $1.99/min. Although I like The Sims 4 too. Give them another chance. The full version of this game, only came out late last year. Early to mid last year, this game was only in Alpha.
Updates to this game are free. But DLC may not be.
I recently watched a video with the new spooky DLC. I like the clouds fog and rain. It's NZ$13.99. That's less than even one hour's pay on the minimum wage in NZ/Australia. I really want a water expansion DLC with swimming pools and water slides. Popular Youtubers want it too.