Like many people, I began my RPG career with AD&D, where what your character could do was heavily impacted by your character class.
I would them move to classless systems (starting with GURPS) in the late 80s and early 90s.
I enjoyed both - the classless systems allowed an enjoyable amount of customization, while the class systems allowed for heroic archetypes that provided shortcuts for playing.
When D&D 3rd edition (and later Pathfinder) came along, I played them a fair amount, but always found myself dissatisfied. Part of it was that the games tended to favor a style of play where obsession with character builds often got in the way of the types of role playing that I enjoyed (and yes, there are many people who really enjoy this element of the game), but a bigger thing was that the classes seemed to not mean much - the pinnacle of this for me was playing with someone who had created a rogue that, through a combination of feats and splatbook rules, was a competent “shadow mage” type, but had no classic rogue skills (other than stealth, which was achieved by magic rather than skills).
For me, it felt like there was little point to having classes if they were so formless. And having played and greatly enjoyed classless games, that seemed preferable.
But, given the success of 3rd edition and Pathfinder, I know that my views are not universal by any means. So, what are your preferences regarding class in RPGs? How much or little do you like class to constrain a character? Or do you want to do away with classes?