I remember that back then (2017–2020), most websites loaded just fine, whether on 3G or EDGE — the only difference was the speed. As of today, even the search engine lite.duckduckgo.com/lite/ (in Google Chrome) barely works when searching on H and 3G mobile networks — not to mention EDGE. When I try to open a website on EDGE, the browser displays the message: DNS_PROBE_STARTED.

did you try text.npr.org or lite.cnn.com;

I assume you are not in the US, since most 2.5g/3g towers have been shut down;

the reason could be bloated client, heavy 3rd party tracking; probably request timeouts might have been tuned to reflect 4g/5g latency/responses to ensure efficient server resource usage.

there is not much you can do with 200kbps these days.