you can do a lot of learning with basic hardware
So so much.
I'm running video calls (Livekit) for ~50 users (dunno how active) through an ancient laptop that doesn't even have USB3. Among other things - the same lappy is also doing email and TLS termination for a HLS stream.
I'm using an old phone, a Google Pixel 3a (that's 4 GB of RAM) as a monitoring solution (Prometheus, Grafana, AlertManager, ntfy).