The Oneplus 6 was expensive but I somehow splurged since I wanted the headphone jack and an OLED screen on an SD845 phone ( I'd get a cheaper Xiaomi Mi 8 if I didn't need the jack ) .
But even though I plan to use the 6 for a long time simply because it's still around the top in performance, I won't buy another device from them. If I want a "jackless" phone, I can get a Mi 8 ( or the next Mi device ) for less money without sacrificing anything.
Oneplus went from a "flagship killer company" to a "what a flagship company should be".
Just because other companies charge hysterical amounts for, HONESTLY, toys which just have basic phone functions for the fun of it doesn't mean you should slowly creep the prices up higher even though the competition is keeping their prices reasonable ( a 100$ and in the future even bigger difference isn't a thing to scuff at ).
If the Mi 8 had a 3.5mm jack, it would be really hard to pick the Oneplus 6 without sentimental decisions especially when you'd take a look at the prices of both. Sure, the Oneplus 6 "has" water/splash resistance but you're doing it wrong if you expose a piece of tech to the risk of water damage in the first place.
In conclusion:
As much as I love the Oneplus 6, I don't think I'll buy another Oneplus phone. I don't judge anyone who will, it's just not my cup of tea.