It mostly comes down to drivers from what I understand but I'm not entirely familiar with all the objections.
I always thought that it was funny that their NICs are much to be desired yet their ASICs power a wide variety of enterprise network switches capable of moving terabits of traffic at low latency.
So yeah, Broadcom is a rollup of two dozen different companies so the quality of one product tells you nothing about others.
Admittedly it's been a while since I had a broadcom controller, but I had all sorts of problems with it. Random disconnects etc.
In my experience, Intel has higher performance and more features (which might be a downside from the point of complexity and configuration) at a higher cost, while Realtek is slower, but cheap, simple and reliable.
The only reason why Realtek dominates is because they are the cheaper alternative. The only reason why Intel dominate WiFI on PC is because they are bundled as part of their CPU sales for Laptop.
Most of the half decent WiFI AP still uses Broadcom. Although increasingly Qualcomm is making inroad. So Boradcom is stuck in the middle of no where in consumer market. They dont have WiFi in PC Laptops, nor do they have WiFi in Android Smartphone. Apple being the largest Broadcom customer for their consumer grade WiFI. And that is why every 2-3 years you may have read Broadcom's intentional leaks about they want to sell their WiFi chipset division because they dont want to play balls with Apple's WiFi asking price.
Don't take this as an endorsement of Broadcom or anything.
Shitty firmware and garbage reference drivers sounds like endorsement enough.