So the only genuinely flat proof tires are airless tires like Tannus. They have gotten meaningfully better, and they definitely have some legitimate uses, but they are still heavier, more expensive, feel worse, and roll slower than pneumatic tires and are a fair pain in the ass too install. Better puncture resistant tires legitimately help a lot--probably the best you can do is something like Schwalbe Marathons with sealant in the tubes. In my opinion heavy duty tubes do little except be heavier.
If you ever shop for a newer, higher end bike look for something with tubeless compatible tires and wheels, as tubeless does really well with thorn punctures.