How do I act dumb at work?

I have tried developing strategies, brainstorming solutions, worried to core leading to breakdowns While collegeaues from IIT/IIM earning double, don't know basic shit I have understood there's no point putting that extra effort. How do I act dumb on purpose? I'm not someone who can stretch work, result and speed are inherent and this is why need advice here.

P.S. company is citing funding winter for no appraisals this year So another reason