The 3B+ has gigabit ethernet, but it's still on a USB 2 bus, so you're going max out at ~200Mbps instead of anything close to 1000Mbps. That's still enough for maybe 10 simultaneous 4k streams, so you should be fine.
Reading and writing to an SD card becomes a bottleneck at that point anyway, so true gigabit ethernet probably wouldn't be that noticeable.
Yeah, good point about the rest of the hardware components, and the streaming rate. I recall that Netflix "Ultra HD" is around 25Mbps, so there's plenty of headroom.
The 3B+ has gigabit ethernet, but it's still on a USB 2 bus, so you're going max out at ~200Mbps instead of anything close to 1000Mbps. That's still enough for maybe 10 simultaneous 4k streams, so you should be fine.
Reading and writing to an SD card becomes a bottleneck at that point anyway, so true gigabit ethernet probably wouldn't be that noticeable.