Originally Posted by
erila
I fly Ryanair very regularly, and can confirm that they don't weigh cabin luggage
This is something you would only be able to confirm if you had flown on every single route Ryanair operates.
All you are able to confirm is that you have never seen them weigh cabin baggage on the routes that you fly.
I used to fly STN-LBC (don't any more) and have seen them weigh cabin baggage at both airport. The don't routinely weigh every single item, but they certainly do spot checks - and it's not just with items that look heavy.
Please refrain from making such sweeping generalisations.