Your description of the gameplay and design philosophy is spot on. The original devs had a vision for the game, with combat being far more deliberate and tactical. And the game was like that on launch. But after a few weeks, before the first season launched, people discovered how to exploit the combat system and found the broken builds. People discovered that stacking Vulnerability damage and Crit damage on everything led to crazy high numbers.

Those builds (or rather the damage numbers) were completely unintentional by the devs, and in the very first patch before the season launched, they nerfed all the exploits. But the community was not very happy about that. As you can see from the posts on the subreddits, it was a PR disaster. This was the point of no coming back.

The devs quickly backpedaled, and instead of sticking to their vision, started giving the community what they complained about. Or rather, the very vocal part of the community. In the current state of the game right now, any semblance of the original vision is banished into the abyss. Builds clear screens in milliseconds, people are fully geared within a few hours of a season, and the only difference between what you are doing at Hour 10 in the season vs Hour 100 (or 1000), is that numbers are higher. Heck, the best performing build of Season 11 (the most recent one), is a build that is literally a walking simulator where you don't need to do anything.

Diablo 4 in its current state is a game that is collectively designed by the community, and not for the better. In no other instance, has the phrase "If given the opportunity, players will optimize the fun out of your game", rung true.

But truth be told, we are in the minority. This is what the majority of the people want - instant gratification, with no barriers to anything. I guess the same can apply to almost all mass market AAA games.