Jagex thought they knew better than the players what the game should look like, and overhauled the whole game to the point it was unrecognizable. It took a massive loss of paying members to get them to finally release 2007 version of RuneScape back.
Even now, OSRS has double the amount of players that RS3 has. Lol
Turns out the 2007 version of the game was ROUGH for a lot of reasons - they picked the time because, IIRC, it was the most complete backup they had.
OSRS has now had nearly a decade of consistent updates, a large team, and typically 10x the online player count of the "modern" game. The catch is that OSRS is not the 2007 version of the game, it's an alternative update timeline which broke off at the 2007 version of the game.
But I can't think of a way to verify those numbers, so agree to disagree.