Every firearm will need parts replacement eventually. Given that’s the case and I have yet to hear of someone wearing out an aluminum frame on a 22LR pistol I still believe your concerns are moot, as has been pointed by others too. The only way to never wear out a pistol is to never shoot it, which then defeats the point.
If it bothers you that much then buy a Ruger Mk series pistol to ease your concern. But I stand by the notion that it’s unnecessary and a construct of your own beliefs more than reality.
I'm pretty sure everyone will agree there are real differences in quality and expected longevity, amongst various .22 pistols. "They all wear, so therefore there is no difference" is not an argument I take seriously.
It is possible that I will never even get close to the expected maximum round count of a stainless MK II -- in fact that's the idea. I'm less confident that I could treat one of my excellent aluminum-frame Beretta 71's in exactly the same way and expect exactly the same result.