Why do people block you instead of just telling you what the problem's?

I had this girl added on Instagram. She was actually the one who randomly requested to follow me first, then she started talking to me and everything. I basically just reacted to it because I assumed she somehow knew me or had a reason for following me

After talking back and forth for a while, I eventually realized she had literally just followed me randomly bahaha

I wasn't interested in a relationship, so I told her that I thought we could just be good friends. She doesn't even live in my city, so I didn't really think it would be a big deal

After that, whenever I posted a story, note, or basically anything on Instagram, I'd notice that she liked it. So I started doing the same with her posts because I didn't want her to feel like I was ignoring her or acting weird about it

Then one day I noticed she had blocked me

No argument. No obvious reason. Nothing happened that I can remember. Just... blocked

And honestly, it bothered me way more than I expected. Not because I wanted a relationship with her, but because I wanted to know why. I'm not even the most talkative person. I can have a really good conversation with someone, get along with them really well, and then randomly lose interest in talking for a while. Sometimes I might want to talk again later. That's just how I'm

So when I realized she'd blocked me, I started wondering if I'd somehow done something wrong. I wanted to ask her what happened, but her account was private, so I couldn't even DM her

Eventually I just let it go

Then later, while scrolling through my Instagram DMs, I came across another chat that just said "Instagram User"

And that's when I realized... oh, I really fucked up

Like, what even happened here?

I genuinely don't understand the logic of blocking someone without saying anything, especially when the only thing that happened was that I didn't want a relationship and preferred being friends

Is this just how people communicate nowadays?