In “Hacks,” the Emmy-nominated HBO Max comedy-drama released in early May, a stubborn 70-year-old veteran comedian meets her match in a self-obsessed, flannel-wearing 25-year-old humorist. The most promising part of the 10-episode series is the unlikely bond between Deborah Vance (portrayed by “Mare of Easttown” actress Jean Smart), a stand-up comic based in Las Vegas, and Ava Daniels (Hannah Einbinder), a comedy writer who has been canceled due to an off-color tweet about a gay senator.