The Ryzen 5 3600 is a 2019 mid-range CPU.
There has been a dramatic increase of performance since then, two big steps with Ryzen 5000, 7000 and the 3D Vcache versions that are absolutely the best CPUs to run MSFS.
If your motherboard can fit a 5800X3D, that would be the best upgrade you can do for little money.*
Also, as suggested, try to limit your settings in order not to fill your VRAM.
