The lifetime doesn’t seem to be that much longer, according to [0] a Starlink satellite’s orbit will decay in around 5 years.
[0] www.businessinsider.com/spacex-starlink-internet-satellites-percent-failure-rate-space-debris-risk-2020-10%
[0] www.businessinsider.com/spacex-starlink-internet-satellites-percent-failure-rate-space-debris-risk-2020-10%
300 km 1 month
400 km 1 year
500 km 10 years
700 km 100 years
900 km 1000 years
Their satellites are 550km, 1000km, and higher.