The Intel 8265ac and 9260ac for example are better than their Qualcomm (ie Killer 1535 aka QCA6174A) and Broadcom (numerous Bluetooth issues to the point I replaced quite a few with Intel cards) counterparts stability/reliability wise. Never had an issue with their WiFi cards. Broadcom doesn’t even have properly working MU-MIMO which when enabled actually drops performance and my experience had Bluetooth issues, unlike Qualcomm/Intel client chipsets. Even router chipset side Broadcom is kinda behind.
I’d say at the moment Broadcom is the worst of the three. All the WiFi cards in my laptops are Intel, even the corporation where my father works all their high end Precision/Latitude notebooks use cards ranging from 7265 to 8265 and they prefer those over QCA and BCM (Broadcom cards) during order for reliability. At moment in my experience router side QCA9984 is the best WiFi chipset (ie in R7800, RT2600AC) and client side Intel 8265/9260ac.
Cellular side however Qualcomm is probably the best no doubt. Enough tests have shown that at least with iPhones to the point I buy the QCA sim free phones.