THE ANSWER
Threading is quick, precise and temporary. Electrolysis is slow and permanent. For a brow shape you intend to keep for years, electrolysis ends the maintenance. For a shape you might change, threading keeps your options open, which is a genuine advantage rather than a consolation.
Why
Threading uses twisted thread to grip and pull hair out at the root. It is precise, which is why it suits brows, and it removes hair cleanly without chemicals or heat. The follicle survives, so the hair returns, usually in two to four weeks.
Like any method that pulls hair, repeated threading can distort follicles over time. That matters mostly if you later want permanent removal in the same area, because distorted follicles take more sessions to clear.
Electrolysis treats each follicle so it stops producing hair. On a brow this means the strays outside your chosen line stop returning at all. The trade is that it is permanent in both directions. Hair removed cannot be put back, so the line has to be one you actually want to keep.
That is the real decision. Threading is reversible by simply stopping. Electrolysis is not.
Is threading better than waxing for the face?
Threading is more precise and does not involve heat or adhesive on the skin, which many people find gentler, particularly around the brow. Both pull hair from the follicle and both are temporary, so the choice between them is about comfort and precision rather than results.
Why does hair keep coming back after threading?
Because the follicle is untouched. Threading removes the hair that has grown; the follicle produces another. The cycle is the follicle working normally.
Does threading damage the follicle?
Not in the sense of stopping growth. Repeated pulling can pull a follicle out of its natural shape over years, which does not stop hair but does make later permanent treatment slower. See why tweezing makes facial hair worse.
What the evidence says
Follicle distortion from repeated pulling methods is described consistently across independent electrology sources. Threading, waxing and plucking all leave the follicle intact, which is why regrowth follows for all three. Electrolysis is the only method recognised as permanent.
What to do next
Decide whether your brow shape is settled. If you have kept the same line for years and are only maintaining it, that is a line worth setting permanently. If you are still changing your mind about your brows, keep threading and revisit later.
If you do go permanent, take less rather than more at the start. See eyebrow and unibrow hair removal.