Why are companies hiring excessive Interns?

Yes, stipend is less compared to full time employees.

This is a common tactic used by a lot of companies to hire a lot of interns, give them a lot of work in the guise of “learning”, offer a few who can do the work and not complain a PPO at below market rates, let go of the rest. Rinse and repeat.

My previous company (startup) hire smart iit/nit college going student give them some stipend and get the work done but the real pain was for us full time employee we have manage them make sure they write quality code help them with Hlds and Llds and the worst one take a lot of follow ups specially during late hours as they will be working after college