You are only helping the entrenched browser monopoly and furthering the dystopia if you attempt to block anything but "approved" user-agents. This is what people like RMS were warning us about decades ago.
Block on traffic volume and request frequency if that's causing a problem.
(And yes, I can't access the site either. No, I will not conform. But I bet anyone determined enough will still get through, just like with DRM.)
I can accept that. I've sat with RMS a few times. He's an interesting and very smart person. There are things he and I agree and disagree on. I'm sure I would never hear the end of it on this one. I'm glad he put the cancer into remission and will have many many more years.
On the topic of browsing with any kind of browser, I would be extra careful using things people have vibe coded or more specifically have not been battle hardened to protect against malicious sites. The reader apps people use I think would be especially at risk of malicious servers if they have not gone through extensive third party code reviews by penetration testers.