3 Mbps should be plenty for many jobs I think? I work remotely with a 3 Mbps connection and it's fine for me.
For mobile dev it seems fine most of the time.
Depends on the job, but I would think for most people on HN 3mbps would be considered painfully slow, which it is.
But even for the less technically apt, consider other common tasks that require speedy broadband. Something like restoring a 100GB iCloud backup to a new iPhone on a 3mbps connection would take over 3 days, assuming the connection (or your patience) could hold that long.
And you certainly won't be streaming your favorite shows in 4k.
That's a fantasy unless you consider 3mbps DSL to be 'high speed'.
And that's not even remote, that's often the highest speed available not even an hour outside of many major US cities out west.