The C64 can output composite video natively (with the yellow, red, white cables). You could buy or build yourself such a cable and then use an composite to hdmi converter box to use your modern monitor. Although I do not know if cheap ones will work with the signal, you have to do some more research on that.
I bet the throtteling is not caused by data scraping but by Twitter not paying their Google Cloud bills and therefore now with the new month they got services suspended.