The idea that rito added this "feature" to encourage cooperation and strategy is bs. The majority of the player base (including myself) isn't skilled enough where pre-planned strategy and play styles are even needed. The games end up being "whichever team's carry plays the safest from the assassins/brawlers of the other team wins."
The real reason rito added required lock ins for picks/bans is because they want to be able to come out after "months of analyzing the new champ select" and say that "TOXICITY AND QUEUE-TO-GAME TIMES ARE WAY WAY DOWN!! WE'RE GENIUSES! LOOK AT THESE NUMBERS!" Previously you had two people banning, 6 rounds of picking champions, and then a little preparation timer. Now, you have preferred champion select (don't get me started), 6 people banning, then 10 people picking champions one at a time, then the little preparation timer. Champ select is way more broken up now, and If they didn't require you to lock in, then they wouldn't be able to pass it off as a positive change in a future infographic.