How an EMI is built
Each EMI pays the month's interest on what you still owe, and the rest reduces the loan. Early on you owe a lot, so most of the EMI is interest.
Tenure is the big lever
A 20-year home loan at 8.5% costs roughly as much in interest as the loan itself. Cutting tenure, or prepaying in the first years, saves the most.
The real cost
Add processing fees and insurance to the interest. For car and personal loans, compare the total amount you pay, not only the EMI.