Its a tradeoff between fan noise and performance, but the reduction in noise will likely far outweigh the performance deficit that entails for most office users.
https://www.notebookcheck.net/The-HP-EliteBook-840-G8-has-one-huge-advantage-over-most-other-business-laptops-but-it-comes-at-a-cost.553412.0.html
This is important information, and I thank you for stating it so clearly. But how can you say that a 20% drop in processor performance is giving up only a "bit" of performance? Ha ha ha.
You forgot to mention the spyware HP will force install into your browser (particularly Chrome), even if you use a clean Windows ISO, that is almost impossible to get rid of. That is a deal broker for most people. But then again most people rationalize it with: "Well, Microsoft and Google are already spying on me, so who cares if HP is doing it?" ::)