The game certainly has changed alot.
We now do have a PVE server and a PVP server where the PVP server is not even anything close to the times before Providence, let alone anything before the days of the TBF system.
Its hard to tell whether its more difficult or not now, it does barely feel like the same game anymore. It depends from what perspective you look at it, I guess. Many new goals and purposes have been created. One thing I can tell, back in the days Heffernan would not survive without starting from scratch every 2 weeks, unlike anything now. So looking it from that side, the difficulty has decreased enormously.