[mattkrause]

"Confirmation bias" seems overly harsh. EEG does actually measure brain activity and it's certainly useful for some clinical/research tasks--if you don't mess it up (which is very easy to do). The trick is that you have to play to its strengths, which involve measuring large-scale activity patterns, like sleep (or epilepsy). If you want to measure something very localized, you need another technique (ideally with a hole in the skull).

In fact, I'd say that there is no overall "best" tool.

fMRI has the best (non-invasive) spatial resolution, but since it relies on blood flow, the temporal resolution is sluggish.

EEG has great temporal resolution, but even with fancy source-reconstruction techniques, the spatial resolution is very poor. It's certainly useful for some things, especially those related to global "state" factors. It's also very portable--if you can control EMI and movement artifacts.

MEG is something of dark horse: very good temporal resolution, and the spatial resolution often good--mostly. Since it relies on detecting magnetic fields, it cannot detect neural (electrical) activity that is radial to it. The other big drawback is that it required a large and expensive system with cryogenically-cooled superconducting detectors. However, the newer OPM detectors are cheaper and work at room temp, so more real-world things are possible.

fNIRS, PAT, and ultrasound seem like they might be good in some applications too.