Encounter rate is static. The game will always make a 1/4069 Pokemon shiny. You're probably thinking of the likelihood that you'd get a shiny and how it changes every time you don't. And to that, yes, every time you reset and don't get a shiny, the percentage likelihood that you will increases. The more you do something, the more likely you are to get the result you want.
I don't really know how else to explain it. The game doesn't increase the rate you'd get a shiny every time you don't, it's always the same number just like it is to say win at a casino. But just mathematically the more you do something the better your outcomes are likely to be