To add on to what else has been said, you can just be blunt and obnoxious about it. Tell them “If a bunch of barely literate peasants in China can figure out Kapital on their own despite it being written in another language, you can read a pamphlet or two.”

People smarter than anyone alive have done more in worse conditions and did us the courtesy of writing down what worked and what didn’t. The Bolsheviks, Black Panther Party, anarchists in Civil War Spain and Nazi Germany, etc. were in life or death situations trying to mobilize leftwing revolution. The least anyone calling themselves a socialist can do is read what they wrote. If you say “I don’t need to read theory because it’s just a book club,” you’re being an arrogant, egotistical asshole.

We also live in an age where there are audiobooks and videos that will read this stuff to you for free, something our predecessors didn’t have. People with disabilities have used these tools to help them understand theory when they struggle with reading. There’s really no excuse.