I hope it will be, and think it has the potential.
It has already replaced the "all" experience for me, and I automatically come here rather than Reddit. On the other hand, most of my engagement on reddit was with hobby/interest communities. Very few of the ones I visited on Reddit have made it across in an active way so far.
One unexpected thing is that I actually enjoy my specific instance and find myself browsing "Local" way more often than I expected.
Yeah, this is my experience with Lemmy so far: it has replaced the "all" experience for me, but all my hobby / interests subs are completely dead.