Please research two things - SPA vs SSR
SPA is a Single Page Application (which most Replit and of AI generated sites are built on by default).
In order for SPA to be rendered, Javascript has to be executed first.
Now most modern crawlers including Google are able to do that, but new sites have a lower crawl budget and thus indexing becomes a challenge.
Google parses Javascript in two stages before it indexes the.
In stage one, it extracts the html generated along with the Javascript. And in stage two, it renders the javascript to get the actual page content (this depends on computing power availability and can take weeks)
https://developers.google.com/search/docs/crawling-indexing/javascript/javascript-seo-basics
To verify if you're an SPA, open your site and right click and select "View Source" (Not inspect element). And see if you see the actual content there or just a single div.
If you're an SPA, you should switch to SSR (not sure if Replit can do it - but you can try prompting)
SSR is Server-side rendering. This renders the entire page at the server level. So, on a browser and for a crawler, the page loads like a normal html page, all ready to be indexed.
This plus additional on-site SEO integrations, make indexing easier and take up lower crawl budget.