Reblocked 5 years later?

My ex and I broke up 5 years ago now. He’s had me blocked since on his personal accounts on all socials. Honestly I got over this probably 4 years ago.

I still follow his sister on socials and saw she posted on her story that they made a remodeling business together recently according to her instagram page. I clicked on their page that she linked from her instagram story, browsed the page for a second and thought to myself “oh good for them” and didn’t think much else of it. I have no animosity towards him or his family.

Couple weeks go by and I’m at my parents place, and my mom out of the blue asks how so and so (my ex) is doing. She has always asked my sisters and I how our exes are doing because she’s just curious like that lol. I say “uhhh I don’t really know, he’s still got me blocked online. I saw from his sisters page though they they started a remodel business”

My mom asks to see the remodeling page so I go to instagram to search it up and what do ya know. I’m blocked from that account now? And I say to her “oh he must have blocked me from this account too. 5 years later? Really?”

My ex’s sister still follows me on socials so this is definitely his doing from their instagram account. We broke up mutually.

My question is why would someone go to that much effort to block their ex everywhere after all that many years? I don’t think he’s dated since. Either he really hates my guts or he still isn’t over it. would love to know what it likely is from a guys perspective?