Gawd: this topic has been beat to death. Naive new road riders, industry apologists and marketers come out here (hair on fire) shilling discs for every rider for every application. But for most riders, discs are simply too heavy, fussy and expensive. But, unlike rim brakes, discs lock most riders into their shops for routine and reoccurring brake maintenance, so I guess that is a win for the industry.

Plus it allows the industry to charge an extra $500 for pretty much every bike, notwithstanding the actual costs.

The two dominant forces in the bike industry are:

1. Legal butt covering. The objective here is not necessarily make things easier or safer, but make sure that any customer accident or loss can be solidly attributed to the user. Example: thru-axles. In actual use, they are an annoying PITA, and do not resulting in any increased 'stiffness' or performance, but they shed all responsibility for wheel installation mistakes onto the consumer.
2. Inventory churn. Every few years the industry has to come up with a new shiny bauble that causes riders to shed their perfectly functional bikes. For the road, this includes: 1 x systems, suspension elements, fat tires and of course discs. And of course the silly game of adding another cog to the cassette every 7 years to render all previous generations of bikes 'worthless and obsolete'.

Another key advantage of this churn is that it allows the manufacturers and retailers to basically walk away from any bike more than 5 years old, thereby forcing a new purchase decision. As heard in shops across the First World: "10 speeds?! That is like 10 years old, and we cannot source parts for this any more. But let me show you our 2024 bike lineup...."