The weird thing is... my CPU usage never goes past 23% and the graphics card never gets past 30%
I don't know why this could be. I've fiddled with the user.cfg file to make use of all my CPU cores, but this doesn't seem to make any difference.
I just want the game to use the hardware that it's running on

...and no, I don't consider turning down my settings a fix. I shouldn't have to do that, and it makes the game look intolerably worse. If anything I should be able to turn it up much higher...
...Also the fact that it's an older engine is no good excuse either. Source is an old engine and I can run HL2 at several hundred fps.
my pc stats:
CPU: AMD Ryzen 5 1600 (14nm) 3.2 GHz 6-Core Processor
CPU Cooler: Corsair iCUE H150i RGB PRO XT 75 CFM Liquid CPU Cooler
Motherboard: MSI A320M PRO-VD PLUS Micro ATX AM4 Motherboard
Memory: TEAMGROUP T-Force Vulcan Z 32 GB (2 x 16 GB) DDR4-3600 CL18 Memory
Storage: HP 2DP97AA#ABC 120 GB 2.5" Solid State Drive
Storage: KingSpec P3 128 GB 2.5" Solid State Drive
Storage: Seagate BarraCuda 500 GB 3.5" 7200 RPM Internal Hard Drive
Storage: Western Digital Caviar Blue 1 TB 3.5" 7200 RPM Internal Hard Drive
Video Card: Gigabyte EAGLE GeForce RTX 4060 Ti 8 GB Video Card
Case: Phanteks Enthoo EVOLV ATX TG ATX Mid Tower Case
Power Supply: Corsair RM1000x (2021) 1000 W 80+ Gold Certified Fully Modular ATX Power Supply
Operating System: Microsoft Windows 10 Home OEM - DVD 64-bit
Wireless Network Adapter: Gigabyte GC-WBAX210 802.11a/b/g/n/ac/ax PCIe x1 Wi-Fi Adapter
Case Fan: Corsair ML120 75 CFM 120 mm Fans 2-Pack
Monitor: Acer K272HL 27.0" 1920 x 1080 60 Hz Monitor
Mouse: Razer Basilisk V3 Wired Optical Mouse
Headphones: Logitech G435 Headset
Webcam: Logitech C920 HD Pro Webcam