Why is my Blender project so slow?

My blender scene consists of 6.2million tris, existing out of mostly furniture, some plants and stuff.
And for some reason blender is REALLY low in FPS especially after I CTRL+Z or export a mesh!

I want to export my meshes one by one to UE4, but this takes so long about 20-60secs to export one model!
This task is supposed to take about 1 hour, but this will take an entire 6hours!

Looking at my taskmanager, i can see that Blender is mostly using RAM almost no CPU and GPU.

These are my specs:
Nvidia GTX 1080 8gb
Ryzen 3900X 12core CPU

And Blender is installed on an M2 SSD and the project runs on that aswell.

Even rendering the project in the solid grey “material” mode instead of “texture” is not faster, maybe only a couple of fps.

I think my blender is bugged, can someone help me out because my speed is shit right now!

It’s hard to say without a file, but I would look like at the modifiers if you use any.
That much ram makes me wonder if you have adaptive subsurf turned on.

i already figured out the issue, a beginners mistake LOL.

the problem was that i didn’t check “selected objects” when exporting, so it exported my entire scene of 6.2million triangles that made Blender hung up everytime.

still weird though that blender uses almost no GPU or CPU.

Also about the RAM, no modifiers are enabled, i collapsed all of them.
The RAM comes from using 4K textures i think.