Swifts have a frontal impact rating of 3 stars/driver side and 4 stars/passenger side (out of 5).
1995-2001 Metros rate 4 and 4.
No side crash ratings on either model.
Do the math. The vast majority of cars and trucks on the road weigh in at 2 tons+. These cars weigh about 1800 lbs and have limited side impact protection. New side impact regulations in 2002 were a big reason why they were no longer imported to USA. A comparable Toyota Yaris coupe weighs 500 lbs more.
Mostly due to safety improvements. You are much safer in a Swift/Metro than on a motorcycle, but newer cars are safer still. How you balance the safety/mpg equation is different for everybody. YMMV.