I agree that quality matters more than quantity but I don’t think it’s applicable for every trader. For instance, 30-35 trades a day won’t be too much for a day trader whereas it will be a lot for swing traders even in a month. Therefore, It’s your trading strategy that determines how often you should trade and it’s not good to exceed that limit either because of greed or lack of discipline as it doesn’t let traders perform well.
In forex both quality and quantity matters. A trade with good trading plan if don't have significant lot size might miss the chance.