Seldom drive then just stick with the tyres lor. Why want to waste money? Or you can go online and find some used tires.

If you are worried then have it replaced. You didnt mentioned crack earlier, just saying its been 8 years. I just had a tyre change for my 8 years old car. The original tyres were manufactured in 2013, roughly 10years++. I know what my usage are, just driving around cities in KV at reasonable speed on weekends. Hence personally I would just use it to 10years since my mileage per year is only 2000KM at most.

The most important is still you felt at ease when using the car. After all, car tyres are due to change sooner or later. It is just a matter of when, not if.