@aditya.a.s.singh.18 One plus has started rolling updates on 13 Dec and it contains November security patch only. In some time we will also be getting the security patch and some improvements. Don't just claim anything before checking facts.
Also i too had the motherboard problem and gave the device to service center, and they replaced in 5 days. I know it feels frustrating having problems in your newly bought phone, but believe me it will get better. Asus is working on patches and improvements, although slowly but working. We got the HD streaming in prime. We got Android 10. Camera quality should be improving in upcoming updates. Just be patient.