The average smartphone lasts two to three years. Toward the end of its life, a phone will start to show signs of slowing down. It’s important to take a look so you can prepare for what comes next
I bought used redmi 4a and that is why it is slow. Should I buy a new one or used that has latest model?
Why not when you need it besides it is already an old, used model. You can buy cheap brand new or a quality used phone.