I agree the OP6 is great (my girlfriend is still using hers), but I was still on my OP 3 like a year ago, until future ROM updates were deemed impossible thanks to Qualcomm binary blobs.
It's a real shame it's all over now. The OP 9 Pro was the last OnePlus phone made in their old way (or close to it) - not too expensive, well built, close to stock ROM, easy to reflash, decently repairable. Hopefully it lasts me as long as the 3 did because currently I don't see anything else like that on the market.
https://oxygenupdater.com/article/438/
Yes, I am still on my beloved OnePlus 6 running Lineage and had been looking around for a used 7 or 8 for 5G capability (I'm a bit sketched out by the overall throttling hoopla of 9th gen). Perhaps it's time to expand the search beyond OnePlus.
After OnePlus decided to stop publishing factory images, I decided to stop buying their phones. It's a real shame, because they really do make some great stuff and prices are quite reasonable generally speaking. I used to buy a new OnePlus phone nearly every year. The OnePlus 6 was one of my favorite phones of all time.