I've heard the issue about disregarding canon many times and it just doesn't make sense. We're talking about TOS-era canon, which frequently hasn't been treated as being canon.
There was little consistency among the writers in TOS. For example, stardates are pretty much all over the place in TOS. In TNG, stardates began with 4, the second number was the season of TNG, then the remaining numbers were increased throughout the season. For example, stardate 43996.1 would be near the end of TNG season 3, or right around the time of The Best of Both Worlds.
Starship speeds were much faster in TOS, as indicated in Let That Be Your Last Battlefield, in which two aliens take over the Enterprise and take it to a planet on the other side of the galaxy, in uncharted territory. Perhaps the aliens had Q-like powers, but it leaves the problem that the Enterprise would have been stranded on the other side of the galaxy. They were back in Federation space for the next episode, rather than being stuck 75 years away from Earth like in Voyager. In That Which Survives, the Enterprise was hurled 990 light years and is able to travel back in a matter of days. For comparison, in Q Who, the Enterprise-D was hurled 7,000 light years to system J-25 in the Beta Quadrant and was over two years from the nearest starbase.
Other TOS-era things like the galactic barrier and the great barrier (Star Trek V) appeared. In TOS and Star Trek IV, time travel is possible by slingshotting around a star to attain faster speeds than can be produced by the ship's engines under normal circumstances. These things were never spoken of again after TOS and the TOS-era movies.
By the time of TNG, there were more formal rules for the writers to follow. That's why TNG and later series are generally more consistent. TOS-era canon was already disregarded in some ways by TNG. I just don't think canon is the issue here.
Instead I propose that Gene Roddenberry established standards for Star Trek and rules. An example of this is not showing conflict between members of the crew outside of rare situations. For all the criticism of Rick Berman, he was very strict at following Gene Roddenberry's standards. Many people would say he was far too strict about this. It included things like insisting that Voyager follow an episodic format rather than larger story arcs. Berman is criticized for refusing to deviate from Gene Roddenberry's standards enough, causing the franchise to become stale.
Alex Kurtzman and others have been willing to ignore Roddenberry's standards and break many of his rules, things that fans became used to in the Rick Berman era. The result is a product that no longer looks and feels like Star Trek. I have no problem with the updated aesthetic of Discovery, and the bridge of the Enterprise looks amazing. Ignoring canon makes sense in some instances, otherwise TNG wouldn't have done it. But the writing is so different and that's why it just doesn't feel like Star Trek.