2018 in .io games had a steady decline, and when 2018 was reached, there was less successful or original games. A lot of this is due to Fortnite, with many .io-focused YouTubers jumping ship. This didn’t help newer games, but there are still some that gained popularity and traction, from then to now.
Keep in mind, I did a lot of research to see what .io games were made in a specific year and so forth. If a game has not appeared on this list, it may be in the other videos.
Note: Some of this is my opinion and with reasons. If you disagree, feel free to comment.