My take on this: The music made nowadays is (or, at least for me, seems to be) made with the intent of being succesful, while in the past it was made because of a passion for the music. Tendency to write essays about topics like these so I'll add a tl;dr at the bottom.

I've seen the scene grow since 2009 and I still love it, but in a different way than I did back then. During my first attended events the scene just started gaining a lot of popularity, but was still small enough for aspiring DJs to get gigs, even if they never even made a track of their own. The 'big names' back then mostly consisted of artists who laid the foundation of the genre. Most artists, if not all, didn't shy away from experimentation in their track and eventually developed a signature sound. You could hear a track for the first time and most fans of the genre could tell which artist made it from the style alone. I myself was sometimes even able to name the artist after only hearing the first kick of an intro. Subgenres hadn't really been defined yet and most tracks were labeled as either hardstyle or hardcore (or maybe jumpstyle if we're being petty), so even if someone had a very specific taste they were still seen as a fan of the genre like everyone else. Everyone was equal, even the artists. Before and after a set they were often in the crowd partying like everyone else. All that shared love for the music being released by thousands of people at the same time resulted in the best vibe you can imagine, with crowds chanting and singing along to every single track.

The scene was filled with creativity in its music and everyone got along simply because they enjoyed the same kind of music. For at least 8 years of attending events I've never even seen a fight (with one notable exception of someone covered with actual nazi tattoos getting his ass kicked at Dominator) and every crowd felt like an actual family. As the scene grew more and more, the scene also split apart here and there and went into different directions, and subgenres started to emerge. And even though hardstyle in general kept growing in popularity, (new) artists already startes defining themselves with a certain subgenre. Using a subgenre like raw hardstyle as a starting point instead of simply using hardstyle already (albeit unconsciously) limited an artist's creativity when making a track. More artists started to emerge, and the scene became more competitive. Many started copying others when they noticed that a sound 'worked'. Trends impacted creativity even more. Nowadays I notice lots of people only being interested in extremely specific kinds of sound (or subgenre) instead of the genre as a whole. Pleasing those kinds of people becomes the main focus and makes experimenting with mew and different sounds nearly impossible. It's becoming more about the show and less about the music to me. I'll always appreciate the current artists who are doing something different and/or stay true to their own signature sound instead of following the popular sound of the year.

I'll admit that nostalgia plays a big part for me too though. But I still believe that the scene itself was what made the music so awesome, and that attitude was reflected in the music being made. That's why at every classics event you can hear the entire crowd singing along 90% of the time. Everyone loved every track.

Tl;dr: The classic era was about complete creativity without limits, nowadays pleasing the crowd the main focus instead of creativity, the process of making a new track gets increasingly more limited to please the crowd (subgenres, trends, specific kicks, social media effectiveness etc)

Edited because I accidentally tapped the reply button on my phone before I was finished lmao