The concealed mechanisms of Google's SERP ranking algorithms elicit all kinds of questioning and speculation from site owners even if they had previously studied a fairly thorough course in basic SEO techniques and logic. For example, one might speculate on there being a certain "momentum" factor possible within Google's indexing and ranking rules. If an immense number of quality SEO initiatives are committed and that results in the website placing somewhere within the top page of relevant SERPs, some may speculate it is possible that the website could continue to rise steadily even without any further new SEO or content updates. It is not always clear whether Google continually re-indexing a page will not result in a long succession of minor ranking increases for it because the crawlers would technically be registering the same quality of SEO on each occasion.
It can probably be said with certainty that these speculated increases will not be anywhere near enough for a website's long-term prospects when its competitors are constantly delivering new and high-quality content to maintain their own SERP positions relative to each other. Alongside routine content expansions, websites that can sustain a level of success are rewarded by the algorithms for adhering to a consistent direction in which their content pieces topically complement each other. When setting pages up so that they are connected through internal links, it is important for giving context to Google's indexing procedures that the pages discuss related aspects of shared topics.
The effects that one's SEO efforts have on their website's SERP placement opportunities will naturally be blunted arbitrarily by what the competition does to get ahead, but Google's perpetual stream of changes to its algorithms represents a disruptive factor that lies even further beyond the site owner's predictive ability. Even if the site owner capitalizes on strong SEO and is able to match the website's toughest competition for a time, Google itself can institute unspecified rule changes that affect websites' rankings in general and can hit some sites harder than others. Websites should therefore always be monitored for SEO-related traffic shifts using analytics tools. For more information click here https://www.reddit.com/r/SEO/comments/e1fgoc/howdoesseoworkovertime/.