Jagex is adding lesser content in their games. This isn't a new phenomenon, but it is steadily growing. It is content that you can only do RS gold a certain amount of before you can move to the next. But, it usually gives you more rewards, such as daily training events like the circus or random events like the evil tree. There is also some xp games such as Troll Invasion, which can be done every month only.
Instead of adding the typical extra level to a skill, similar to what living rock caverns did for mining (for instance) The trend today is to add something that is able to be performed at a variety of skill levels for varying xp, like fish flingers. This is good because you can't grind it and thus reduces the impact of bots. It is possible to get more xp if you are capable of timing your training. To get the most benefit from your xp, you feel obligated to cheap RuneScape gold do as many as possible.