If you really want native ActivityPub mirroring of your site on Mastodon, you might try @pfefferle’s ActivityPub plugin (along with his NodeInfo and Webfinger plugins). I still need to tinker with my own set up for better formatting, but you could follow my WordPress site @chrisaldrich
A while back I did set up a system that uses IFTTT to target my micropub endpoint for syndicating some content from silos that don’t have good/easy APIs or methods into my website. Generally I do this as private posts so I have the data and selectively post it as necessary. These days I primarily do this with my Hypothes.is annotations to my site, though only a tiny fraction of the 12,000+ is publicly available: https://boffosocko.com/kind/annotation/. Currently only about 1/3 of my 45,000+ posts are publicly viewable on my site.
Eventually someone might build Micropub as a Service so you can sign up and give it social silo accounts to have the service PESOS copies of your content to your website.