A faster way to make money fishing is through the p2p fishing guild. In f2p, fishing lobsters/swordfish from Karamja can earn you around 20k an hour (no concept on this one). The rate of p2p is twice as fast. This is because the bank is located close to the fishing spots in OSRS gold the guild. There is also the possibility of fishing for shark and monkfish that can bring in an extra income per hour. F2P fisherman earn 100k, while the p2p player can earn between 200 and 300k.
Mining is exactly the same. The mining guild of P2P is still a fantastic location to mine coal and mith. However, only a only a few people reside in the world so it is always yours. There is the option of teleporting to the wild which makes it more secure and easy to get access to the mines. F2P players can make 100k from mining. A player who uses p2p could make 150-200k.
The higher levels are where p2p really excels. You can find small teams if you have at minimum 90plus combat statistics. Slayer is also a great tool to earn money. I used to make about 400-500k an hour from green dragons as a level 110 player, and also gain decent combat experience at the same time.
Jagex discovered that they did not need rare items to buy RuneScape Mobile gold be used in Runescape. It was not their plan for what were supposed to be humorous festive items to become the more valuable items in the Runescape economy. Jagex is likely to get its wish, as rares will eventually be discontinued.