New or used camera lens

[Ramseys]

To quote a famous Scotsman, "You can not change the laws of physics".
In a zoom lens you have extra glass to absorb light, as well and extra surfaces to reflect said light.
And lengthening paths for the light to travel.
So unless you pay really big money, all zooms are slow. f 4 if you are lucky usually  5.6.
Prime lenses, (one focal length) are much faster for a lot less money.
35mm, 50mm, and 85mm can  all be had in f2 or faster.
Some 50s go all the way down to f1.2 (Canon actually had on that went to F .95!
In case you have an extra $4,000.00 laying about.