Then we have the new characters introduced in 2 and 3. Did most audiences really care about Holdo, Rose, the literally unnamed DJ, Jannah, or Zorri? Snoke had potential but that was cut off before anything could grow.
The difference is in TLJ the secondary characters move the character arcs along, whereas in TRoS they’re just kinda there.
In the end, there was no real arc for Finn, so that renders most of TLJ’s characters kinda there. Canto Bight, DJ, Rose…if Finn HAD died in TLJ, it would’ve been at least some form of resolution. The fakeout is basically the end of his character path in the sequels and it’s pretty weak.
Finn had a clear arc in The Last Jedi, and the clever thing was it was inverted from Rose’s even though the same experiences teach them the lessons. Rose and Poe’s arcs are to go from an “at all costs” approach, ready to sacrifice everything, to understanding that sometimes doing whatever it takes isn’t the same thing as doing it at all costs. Finn’s arc goes from a man without a cause, driven by fear, to becoming someone that understands there are things worth fighting for, even being ready to sacrifice himself. A lot of people say his arc is ruined since he doesn’t sacrifice himself, but that’s not true since he was actually ready to sacrifice himself. He was still making that choice.