Due to the way Twitter works, blocking people is the only way to guarantee that you won't see tweets from someone you don't like. Everyone should do it more. Twitter's safety measures are notoriously lacklustre, but if someone's in your mentions when you don't want them to be, you have a couple of immediate options: you can either mute or block them.
Muting prevents you from seeing other people's tweets when they tweet at you, whereas blocking is seen as a more drastic measure, where people can't engage with your account at all. I don't agree that it's drastic.
The problem with muting is, while it stops you from seeing a particular user's tweets, it does nothing to stop them from tweeting at you. You might check on the replies to a particular tweet and find that someone has been engaging in an aggressive argument with someone you've muted, continuing to clog your mentions even if you thought you had solved the problem.
It also does nothing if someone is combing through your tweets looking for things to show their followers, to get them to also tweet at you. What started as a small problem originating with one user can then turn into a much larger problem, coming from a mob.
The other issue is that a mute doesn't stop you from seeing tweets from an annoying account. When everyone was falling over their asses about Da Share Zone, a satirical Twitter account that posts messages about anxiety or every day life experiences over bizarre images of skeletons or dragons, I wasn't as into it.
I tried muting the account, but other people's retweets were still clogging up my feed. Rather than yell at my friends for enjoying something they enjoyed, I blocked Da Share Zone. Nothing against that account, I just didn't want to see it, and I prefer not get annoyed at posts online if I'm able.
Blocking is also seen as cowardly, and that is a downside that I can sort of understand. It feels like you're letting someone else win: they got to you, so in the game of "who cares the least," you're the loser. The thing about that, though, is that when someone wins a game, the game is over.
Even some of the more persistent angry people who show up in my mentions, the kind who take a screenshot of the block they've received to tweet something like "I guess I touched a nerve," lose interest once there's a stumbling block for further engaging with me.
Anger over being blocked isn't really about losing access to what someone thinks. Let's face it, it's hilariously easy to continue to read people's tweets once you've been blocked. Open an incognito browser and head to their page — you're done. What seems to bother people about blocks isn't that they stop blocked people from reading what a person has to say, but that they can no longer tweet at the person who blocked them. It's about an entitlement to a person's time.
The block, and only the finality of the block, is a reminder of this important truth: no one, ever, in any circumstance, is obligated to engage with you. What do you think is going to happen if you tweet something aggressive, hostile, or outright mean to a stranger?
That they're going to suddenly devote a portion of their busy day to a person who wants to yell at them? Even if you had a very good point, and the block felt unwarranted, it still tells you a lot about the person you were talking to. Now you know that they refuse to hear you.
A common criticism that I hear about people who are prone to hit the block button (such as me) is that they're encasing themselves in an echo chamber. This baffles me. It's not as if Twitter is the only form of outside communication available. Also, how would this supposed "echo chamber" even be possible to create in my day-to-day life? Ultimately, I see it as an act of kindness to myself to not read things that make me angry.
Sometimes, when I block people, I feel like I'm doing them an act of charity. You appear to not like my tweets. Now you can no longer read them. Fly, my child, and be free.
Being blocked is neither a badge of honour nor a grave offence. It's just something people do to make their online experience a little more pleasant. It doesn't stop you from reading people's articles, sending them emails, or even publicly disagreeing with things they have to say. In fact, offering a counterpoint to someone that isn't directed at them specifically, without the expectation that they respond to you, is a perfectly fine way to engage in the so-called marketplace of ideas.
You don't always have to block people. But for the person who is unreasonably angry, the person who is trying to make you defend an argument you're not making, the drive-by troll who wants to "trigger" people or just someone you plain old don't like, blocking is sometimes the best option. Go ahead and block them. You're doing yourself, and them, a favour.