It's kinda brand loyalty, but not exactly. For a long time Intel was the only CPU option worth considering. It wasn't until Ryzen and IIRC Zen 2 for people to realize that AMD is back in the game. Same thing with Nvidia, they are a de-facto monopoly on GPUs. Raytracing happened because Nvidia willed it. AI upscaling and framegen happened because Nvidia willed it. Radeon is stuck perpetually playing catch-up. Which would be fine if you don't care about this, but they also can't fucking price their shit.
They kind of are (were

) though. The difference isn't big enough to consider Radeon istead of Nvidia given the difference in support for coolest newest shiniest tech.
Funny part is AMD is in the lead in consoles and the like with APU. And as of recent years, EPYC processors started overtaking Xeon in servers because of better energy efficiency.