Actors interested in their craft will take any job that challenges them regardless of its marketability in order to build a body of work over time.

It easy for me as an outsider to say this (moreso in hindsight) but Biggs should've realized there are far more character actor roles (see: Dafoe, Oldman, Swinton, Martindale) than leading actor ones.

So while I haven't seen Biggs in anything for decades, meanwhile Dano and Plemons are drinking his milkshake. They drink it up!!