6 mbps internet speeds are horrible

I’ve been downloading something that’s only 8 gbs, and it’s taken 8 hours to download just 24% of that. with my old internet (charter spectrum) I could download something as high as let’s say, 30-40 gbs in an hour or even less. Also if I have as many as just 2 different devices streaming movies on the WiFi at the same time, they both start to drop resolution or just become non available. I’m sick of the horrible WiFi speeds.