SpaceX

Info provided to FCC for the initial testing constellation of 1,600 sats. Per sat max. throughput is roughly 20 Gbps.
So that means, if you as user have 1 Gbps link, your link will be capped at 1 Gbps but same goes for others. You can have 1000 people, each with 1 Gbps link and still be bellow 20 GBps per general usage. Not everyone surf / use / whatever in same time. When you click website, (download data), 99% of the time you read and consume the content, you dont click 100% of the time all the time. For sure, video downloading or whatever will use more data, but you can still manage that. Future satellites will be even faster and will have laser connection between them (First gen, dont have that, as far as I know), so things will only get faster as they learn things.
For example, let's say you watch 4K video from netflix or youtube, you would need 25 Mbps - 20 Gbps is 20.000 Mbps - so if we would use max 1 satellite we could have 800 people watching 4k content in same time. For 1080p you would need 5 Mbps - so that's around 4000 people watching videos in full hd in same time. (This is just aprox, in real life there is bunch of other problems that makes no sense to talk about it now).