Changing MMR into a league system was a disimprovement.
Changing solo/duo into dynamic queue was a disimprovement.
Changing the warding system is a disimprovement. Before, investing gold for wards is a trade off, nowadays people spam wards without a second thought because they are free.
Changing the jungle system was a disimprovement. The jungle timers just reduce the skill level in this game. Also the new jungle mobs don't really offer more diverse choices on what to smite because 99% of the time its obvious what to smite. The new jungle items is just to force smite to have a bonus on champions is making sure there isn't a trade off between potentially losing damage on champions and securing objectives ( although smite was still mostly always required ).
Most reworks are just terrible, and you don't even offer skin refunds when the champion is completely different. These reworks are to remove silences and reduce the number of targeted abilities.
Most changes you have made have reduced the strategy in this game and make decision making quite brain dead. The only thing you want are champions that can make big plays, and remove mechanics that can shut down these champions that make big plays ( like silence or targeted abilities ) Too bad less and less people watch LCS anyways. High elo players also play on smurfs rather than solo queue on their main accounts because who would want to roll the dice with dynamic queue.