Personally see this chart as an estimation of computational performance and understand the limitations. On the other hand it does provide a trend if you look at it over a longer period.

Exactly. FLOPS might be the the best measuring tape we have on hand at the moment.
There seems to be two forces influencing changes in the graph:

• total hardware capabilities
• parallelization / optimization of WUs in different batches (especially for GPU)

Thanks for periodically putting together all these statistical data! Upvoting is the least I can do as a thank you.