There are different types of flash storage:

  * SLC - 1 bit per electrical cell
  * MLC - 2 bits per cell
  * TLC - 3 bits per cell
  * QLC - 4 bits per cell

You need SLC cards if you really want something to be long-lasting. You can find some at specialty places like Digikey, or labeled as "Industrial" in normal channels (i.e. Amazon sells both Kingston and Samsung 8GB industrial cards).

They are both smaller capacity and more expensive, though.

Also, if you're using a stock distribution not intended for a Pi, you probably have quite a lot of logs/etc churning, which can be cleaned up. If you aren't doing much with the Pi except a few common services, check out DietPi.