For most people once their connection is fast enough that any given thing they try to do is not noticeably annoying due to slow download speed, their download speed and their monthly data usage are largely independent.
For example, over the 12-17 years I've had Comcast they increased my download speed from 8 mb/sec to 20 mb/sec, then to somewhere around 40 mb/sec, then to 60 mb/sec, then to 90 mb/sec, and now it is at 120 mb/sec.
I don't remember what my monthly usage was back when it was at 8 mb/sec, but from 40 mb/sec onward, and I think maybe at 20 mb/sec, my monthly usage has stayed about the same, varying between 20 to 40 GB/month.
I've always appreciated the faster speed, even though I don't use it to download more. I appreciate it because it means it takes less time to download. For instance, if I'm working at home and realize I need a big file from work to continue it might be 5 minutes to download at 120 mb/sec. It would have been 30 minutes at 20 mb/sec. The former means I can grab it while I take a bathroom break and a refill on my water, with almost no disruption to my work day. The later means a big disruption.