The difference between f/1.8 and f/3.5

Since a couple of months I own a Sigma 18-35mm f/1.8 lens. I know this lens captures more light but how much more and what about comparing with my Nikon 18-200mm f/3.5-5.6 lens.

I captured the same scene with same settings:

- Nikon D7500

- Exposure time 1.3s

- ISO 800

The difference, which is significantly can be seen in the picture below.

The Sigma lens f/1.8 captures 4 time more light as my Nikon 18-200mm lens on 18mm f/3.5.

So f/numbers do matter :)