Has anyone tried Harmony OS?

Unless you live in China I'd probably avoid this. There are enough privacy concerns with an OS made by Apple or Google, especially when layered with additions made by separate manufacturers like Galaxy phones with both Google and Samsung... but at least they're subject to a comparatively free media with large amounts of scrutiny and the possibility of legal action. I wouldn't trust an OS made in a country where the government has the legal right to demand any changes they see fit including back doors, and if they even if you believe other governments have back doors I trust China's government a lot less to keep them secure against random hackers.
This isn't a conspiracy theory, foreign people visiting certain parts of China have explicitly been ordered at the airport to allow them to install a monitoring app on their phones. This has been reported when tech press were visiting the tech-focussed province I forget the name of for some event.
For clarity I don't trust Apple or Google either, I also have absolutely no problem with the Chinese public, but I have little choice but to deal with someone I don't trust if I want any tech products at all so it comes down to who has the most disincentive. At least Google and Apple have their reputation to lose if there's a backlash.

Firstly I'm just sounding a note of caution, secondly this isn't personal politics. I don't trust my own government much less the US one but the Chinese government has a well recorded history of accessing personal data without warrants or oversight, surveilling their own public to a far higher degree than other countries and consorting with hacker groups who occasionally go rogue.
If your opinions differ that's your right but I'd make the same warning if someone wanted to use a service like 23 and me where it's publicly known they go beyond genetic heritage testing and sell data on your likelihood of certain illnesses to medical insurance companies. I'd even give the same warning if the OS was made in close association with the US government, or my own British government.
Treat politicians and governments like companies, they are not your friend.

https://www.youtube.com/watch?v=Id870OPNBUo
So if this is just the built-in screen reader with no tweaks whatsoever, this is probably outright copyright infringement. Hear the VoiceOver sounds? The voice resembles SkyVoice. You might already be familiar enough with it if you've ever used ZDSR. This one has a Britishish accent though.

I understand that and if it came across like I thought that wasn't valid that wasn't my intent. Curiosity is good and you're obviously aware enough of your privacy to make that decision for yourself, I was just adding a warning for people who are less aware of these things. If it does anything differently to Android or iOS I'd certainly be interested in how, innovation is always good.