Some ISPs are known to cheat and give speed-test websites preferential treatment so that the speed looks fine when testing.

Also you are likely on a cable-modem, right? These are a shared medium, so those 1000/50 numbers need to be taken with a huge grain of salt as it highly depends on how much other people in nearby apartments/houses are using it.

Try if at all possible to switch to a home fiber connection, as those offer much more consistent connections and usually also higher upload speeds.

While proxying or tunneling to a VPS can sometime improve international connectivity (as usually VPSs live in machines that situate in well-connected datacenters), the bottomneck of your uplink is still at your 50Mbps connection.

Also are you connecting to the servers closest to you or better within your country when you did those speedtests? If yes, it implies the your uplink is throttled locally not internationally.

Is this cable service? Cable often shares capacity with people on your “block” so when everyone is uploading, your upload suffers. I had real trouble with cable a few years ago where intermittently my upload would throttle so hard that tcp acks would fail to send and my download would tank too. FIOS was the best thing that every happened to my internet!

If a speed test from opnsense is fine, but librespeed is slow, sounds like it's an issue inside your network.

I'm in the same boat as you. I have 1000/40 and my upload speed is the only reason I have a VPS.