To access BIOS Turn off the computer > Repeatedly tap F2 while powering it on.  In BIOS > Performance > Disable Intel turbo boost. Share results.  Also based on your post you are just using the machine with 4 background apps open. I assume not heavy Apps like Games or Video rendering. Than what's the point of using this machine is machine in performance and unnecessarily waste electricity. You are just pushing GPU and CPU when your use case doesn't need that kind of power.  Performance mode is for Gamers and some enthusiast and this is expected behavior from a Gaming notebook.  I would strictly recommend using Balanced mode in Alienware command center to get a better over life for your machine  
My Laptop is fairly new, about 2 months old, however I did notice something consistent for the past few days. The Laptop reaches abnormally high temperatures while charging, and I mean high. The readings cant go above 100 degrees Celsius but it has gone that high. Every single core tends to go over 90 Degrees Celsius, and I have a cooling pad as well, as I noticed that the fans were working very hard during charging, and I wanted to help it a bit. The fans did stop being as noisy and going at high speeds, but it does do so sometimes. I have about 4 background apps open at maximum these days, and the laptop also Thermal Throttles sometimes to less than 1/4th of its original performance. Laptop Specs and HWMonitor results shall be shown below. The results were taken after running it for about 10 minutes while charging. According to Alienware Command Center and HWMonitor no other part seems to get hot, other than the CPU.  Specs:-  Laptop:- Dell G3 15 3500 Processor:- Intel i5-10300H @ 2.50 Ghz Graphics Card:- Nvidia Geforce GTX 1650 RAM:- 8GB Charger:- Dell 130.0W Charger [IMAGE]    
Processor Reaches high temperatures and Thermal Throttles while charging.