It does something real, it is not the biggest thing you can change, and which switch you have decides almost everything about whether it is worth your evening.
What lubing actually fixes is friction noise — the scratch of the stem sliding in the housing. If your switches scratch, you will hear the difference immediately and it is not subtle. If they are already smooth, you are polishing something that was fine and the result will be exactly the disappointment you are worried about.
So test before you commit. Pull four switches, lube two, put all four back next to each other and type. Ten minutes, and it answers the question for your specific switches better than anyone here can.
The other half is by type:
- Linears benefit the most and are the easiest to get right. This is where the transformation talk comes from.
- Tactiles are risky. Too much on the legs rounds off the bump you presumably bought them for, and people ruin switches this way.
- Clicky — do not. You will muffle the mechanism that is the entire point.
And the honest ranking: stabilisers matter more than switches. A rattling spacebar is the loudest bad noise on most boards, it is four or five parts, and it takes twenty minutes. If you only do one thing tonight, do the stabs. That is the change people actually notice when they pick up your board.