Steve, I am not sure if I understand the nature of your question.
As we know: SFP only supports speeds up to 1Gbps, with SFP+ being used at 10Gbps. QSFP "family" is a larger form-factor, but the switches with QSFP ports still can be used with SFP cables via (inexpensive) adapters. QSFP is for speeds up to 200Gbps. QSFP-DD can now support speeds up to 800 Gbps. The standard was finalized in 2019.
From what I understand, the industry mainly uses speeds below 100 Gbps at this point in time. The move to the higher speeds has just started, and, according to recent Spectra7 presentation, the adoption accelerates this year. One of the hurdles the company is coming through is the slow industry adoption. Next year should be indicative at this point. We are now literally "3 feet away from gold". Just another 6 months... I know we heard this before, but let's be optimistic.
According to the article below, QSFP-DD, by overall rating, is the most advantageous standard these days, so I expect it will be chosen by most of the vendors at this point in time, until the next industry "refresh cycle".
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