I recently discovered that it’s possible to subscribe to Mastodon accounts and YouTube channels in NetNewsWire. Simply enter the URL of the Mastodon account and the YouTube channel as feeds. Unfortunately, no images are displayed, but it’s still a cool feature.
And they (Mastodon) don’t have feeds with boosts and/or replies.
I use openrss for these. They have Mastadon feeds and YouTube feeds without the shorts. Images seem to work in all of them too