[2021] Can someone explain the matchmaking to me like I'm 5?

I ask because something odd happened tonight. I rarely play burn. I like to brew on ladder but it's usually control type decks or tempo. All I tend to see are mono white, Izzet Turns, mono green, sometimes Rakdos treasure or Dimir control.

I decided to brew a Boros (yes Boros) burn list and believe it or not I beat every single Izzet and mono white/green list I faced ( around 7, I know not a huge pool to go by).

BUT, I also noticed after a short time I ONLY started getting matched to Meathook decks, lifegain decks (some Ive never even see before) and other decks with a lot of staying power and hate.

I rarely saw these decks before since Innistrad came out but now since going Boros burn its almost all I see. I've heard rumors the mathmaker tries to give decent matchups but after the start of seeing mostly meta decks it has now almost exclusively given me decks Burn has almost no chance to beat.

Any thoughts on this?

The deck is a ton of fun btw, runs a few hasties like javelineer, stormseeker and sunrise cavalier but it's mostly Rem Karolus/Bloodthirsty Adversary with a bunch of burn spells like shock, roil, sacred fire, play with fire and igneous inspiration. Everything is 3 and under except a pair of Burn Down Houses and a couple Bugbear lands.

Rem is underrated. I've never seen him in Diamond and I'm not sure why. He just makes all your Burn spells better and Adversary just keeps the pressure going.

Anyway, why is WotC screwing with my mojo half the day?