My OnePlus 6 is just short of 4 full years of use, with LineageOS of course. It’s been great and I’d keep it for another few years if I were able to buy a new, genuine replacement battery; all the vendors I see offering one are dubious. The OP6 has excellent hardware for the price I paid for it back in 2019, excellent software thanks to LineageOS support, all while having Dual SIM/microSD (shared slot, used for second SIM by me) and a headphone jack. Earlier, my daily driver was a OnePlus X which I was also happy with for the same reasons. Now that 4 years of battery wear are pushing me towards replacement, I will jump ship only because newer OnePlus phones have impractical display aspect ratios, way too long and narrow for my needs; I consider a phone’s display to be as good as the largest 16:9 rectangle that can fit into it.
Surely LineageOS and similar projects will continue to maintain their own, open source version of the dialer and whatever else gets dropped from AOSP.