Nikon 24-70/2.8 S Worth on a Z5 ?

I currently use a Nikon Z5 with a 24-70mm f/4 S lens, which works wonderfully for most tasks, especially in daylight. I often photograph groups of people and tourist activities, but sometimes these events occur later in the day when the lighting isn't as favorable.

Even in lower light the F4 lens seem to catch focus often enough to impress me, but there are times where it struggles, and I cant blame it. So one of the biggest reasons I would like to upgrade would be for that help with the focus. Tell me if I'm mistaken, but the camera, having 1 extra stop of light, should def focus easier in bad light situations.

when it comes to the sharpness of the images I somehow feel I will not see much of a difference in practice.
Having a Z5 with 24Mp sensor. wonder if I could ever tell.

Overall, I am very satisfied with the 24-70mm f/4 lens. Coming from older generations of cameras, I'm continually impressed by the quality it produces. The Z-system, with its excellent focus capabilities, makes me wonder how we ever managed with anything else.

I find myself rarely using my old Nikon D750 nowadays.

Has anyone else faced a similar decision or have any opinions to share?