The orange pi 5 Geekbench score is ~75% of the i5-8500T used as example, so no - the sff won't be done in a fraction of the time. These CPUs are old and crusty after all...
I do agree that modern CPUs are required for high-load situations.
If you agree, than relative measures of TDP/benchmark at the redline are pointless, ignoring that TDP number are often inaccurate anyway.
What you probably want to compare for most home uses is power at some low idle vs performance at that CPU throttle level. The difference is probably a Watt or two max, which never would justify a brand new SBC over repurposing something headed to ewaste for environmental reasons.
Hard to say without real workloads, but if there are any plans of routinely pegging the CPU, most power efficient strategy is to buy a modern chip.