@flyers - Playing at an average to plus level at any position in MLB is never easy. But the reality is that if one has the general tools to play an effective SS (and Trea has done that...at times in his career), then he has plenty of tools to play 2B. The reverse is not true.
2B is not just as demanding as SS, and generations of play have shown that. Which of course, does not mean that it is easy. It is another up the middle position of real importance. But you almost never see a true 2B (that is not a converted SS already) make the switch to SS and play it effectively. Both cover a lot of ground, but the SS covers more...both get a lot of action, but the SS gets a significant amount more...both are integral to the team defense, but the SS is the QB...and the arm requirements are very different.
Like anything, there is a learning curve. But if a guy can play a solid SS, then as long as he learns the new position he will almost certainly make the transition to 2B well over time. Trea does not have a tools or athleticism issue - he has a focus and fundamentals issue. As of now the betting action should be on him being at SS next season as well.