Classical was about being the highest class in everything, the minimalism of Mozart was very Baroque and marked legacy rather than prime. He was literally like Justin Bieber, applying ideas with the same details everywhere. You hear one Mozart piece and you've heard them all. His most unique piece was his Requiem. Mozart was a servant, he happened to write music, people would hire him out of spite and jealousy a lot of the time especially as this actually made him famous for the time.
Beethoven wasn't romantic (romantic doesn't mean love here by the way, it means personal emotion) at all and classical music was about not being romantic, classical was all about being up their with the church's godliness, Baroque influenced musicians were class in another sense as in snobbiness. Classical music and art rejected church idealism for realist mysticism, if you see the paintings at the time you will notice the pictures were far more representational of god-on-Earth mentality which is poetic. People identified incidence with this poetry, which later founded the symphonic poetry in the mid 19th century which had already taken form in opera which was full of modulation. Classical begins in 1750 with Antonio Soler marking the transition with his Quintet 3 in G major which sounded like a blend of Baroque and Classical.
Muzio Clementi and Beethoven were truly the heralders of the classical music in time, full of rhythm and grandeur than monotonous notes. Bach had already revived Baroque but in a more pleasant way, Mozart would only provide traditional baroque for the sentimental rich. Beethoven's last two pieces were romantic only, founding into life like (timing to breath, to march, representing nature with instruments, etc) rhythm and detail.
Also, the term "perfect music" doesn't exist now nor do it then.
Medieval - musical ideal is relaxing, choral yet gigue like
Renaissance - musical ideal is foreboding choral and the church atmosphere
Baroque - musical ideal is to sound graceful and courtly
Classical - musical ideal is to initiate a dialog with god by demonstrating the best of the best and massive
Romantic - musical ideal is to initiate a dialog with the inner self and the universe, to not share emotion but to use musical representation of the emotions to take the soul on a journey
It helps to understand it you understand Christian history. Though the fact that so many before Mozart sounded like him shows there was nothing truly special about him but the fact he happened to become the most famous. Kind of like Shakespeare, the French for examples rejected Shakespeare because they already had a lot like him and he stood nothing against historical titans, it wasn't until romantic times people used him in classical art/music. I would say that Mozart is the prime reason most don't explore classical that deeply.