How many users return to your site?

I have been working on my site for a long time now and I noticed something different. Back in 2019 when I started a campaign on Google Ads to promote my site the traffic kept going up day after day. Although it was a small increment it was going up nonetheless. Today, may website users are not coming back. I am losing traffic instead. The website is much better than before and I don't know what is wrong. are platforms like Tik-Tok stealing all the traffic?

Have you noticed stuff like this now or in the past?

And what is the normal retention rate for a memes website?

Thank you,
Farris