Comment by sigmoid10

You're mixing up two concepts here: Bandwidth and latency (ping). Latency will always be limited by the speed of light, but bandwidth is currently limited by radio transmission. The upload speed for rovers like Curiosity and Perseverance peaks at like 2000kb/s tops under ideal conditions and is also limited to a few minutes at a time when the relay orbiter is in the right position. With lasers, bandwidth is measured in hundreds of Gb/s. That's the difference between sending an image in less than a second vs. having to wait a day.