Indexing in Google, at least in the past, seems to have occurred faster than it is today.
It used to be that, sometimes, you could finish publishing a blog post, submit it via Google’s Submit URL tool, and within minutes, your new post would be indexed.
I had that experience a number of times, and it was great (especially if you saw your page ranking in the top 30).
It’s been a while since I submitted a new page to Google, but if this person’s experience is any indication, it seems that it’s becoming rarer to see a page be indexed as quickly.
During the recorded portion of the English Google SEO Office-Hours from November 19, 2021, at the 32-minute, 27-second mark, a person submitted a question about this.
(The video below has been queued to the right spot.)
They described their situation as follows (edited for brevity):
“Indexing seems to have changed a lot for me over the past year or two.
“Whereas things were quickly indexed before when submitting them in Search Console, nowadays Search Console submissions seem to have no effect. Rather, it appears on its own in the index after several days or even weeks...sometimes bouncing in and out of the index.
“Why is this?”
Google’s John Mueller, who’s a Search Advocate and is usually the one who hosts these sessions, said he wasn’t sure as to what the immediate reason might be.
“In general,” he said, “the Request Indexing Tool in Search Console is something that passes it on to the right systems, but it doesn't guarantee that things will automatically be indexed.”
He went on to say that, unfortunately, there have been increased abuses of the indexing tool, that there’s a greater quantity of junk, spammy, and questionable URLs being submitted to that tool.
As such, Google had to make the tool and submission process a bit more conservative.
He did say that, over the years, most sites seem to be technically sound, so that bodes well for indexing.
It’s just that, trying to understand the nature of a website...trying to validate it, are reasons it may take longer to see a site indexed in Google.
John also said: “There's still a limited capacity for crawling and also for indexing. We kind of need to be a little bit more selective there, so I imagine [that], overall, that's kind of what you'd be seeing there if we're not picking things up as quickly as you might have in the past.”
So, if you’ve found that indexing in Google is taking longer, it may be because Google is taking longer to filter through some of the lower-quality submissions it receives.