be (still) going strong

To be continuing to be healthy, successful, or functioning properly, especially after a long period of time. Smart phones are designed to become obsolete, but my old flip phone from 2004 is still going strong. My 94-year-old great-grandfather is going strong to this day! I can't believe that piece-of-junk car of yours is still going strong.

be still going ˈstrong

(informal)
1 be still active, successful or working: After nine hours of chess, both players are still going strong. ♢ My car was made in the nineties, but it’s still going strong.
2 be still strong and healthy, in spite of being old: She’s 91 years old and still going strong.