It's remarkable how stable Mastodon is over time - only matched by Bluesky and Threads, which are stable for a completely different reason.
One thing I have wondered about is whether, when sharing a link on Mastodon, all the traffic generated by different instances crawling metadata from the source inflates traffic artificially. That's something I was considering looking at my own data in cpanel, as I received more traffic to my website than I expected, but I'm not sure if it's a potential explanation?