That's not always the case. Sometimes monopolies are born and the companies charge more money out of arrogance that there isn't anyone out there that can "truly" compete with them. But that same arrogance is often what ends up bringing them down.
See Nokia and BlackBerry's arrogance in relation to the rise of the iPhone. They were still charging similar or higher prices than the iPhone for their flagships a few years after the iPhone first appeared, and with no touch features to speak of or anything close to an iPhone experience.
The inertia of success definitely plays a role. For instance, BlackBerry was logically concluding that they "must be doing something right" a few years after the iPhone came out because their financials still looked pretty great, due mainly to the global expansion (the iPhone wasn't in that many countries at first, and Android still had single digit market share). So that's how they rationalized keeping their high non-competitive prices.
I assume something similar is going on at Intel. They continue seeing a large influx of server buyers even with AMD's EPYC being out because of inertia - customers already deciding to buy Xeons in 2017 a few years ago - like say Google which bragged so much about being the first to get a Xeon Skylake. So Intel rationalizes this as "having no reason to reduce its prices, and in fact it could even increase them since it sees so much demand!"
But that logic is going to hurt them a few years from now, when AMD or perhaps some ARM competitors like Qualcomm start becoming more established in the market and they've had a few years of "people hearing good things about their products." Right now the new AMD and ARM chips are untested and the majority of companies like to play it safe.