The lower the rating scale u go the less u will be punished for pretty much everything (in any game), so yea, maybe fullshare doesn't feel punishing enough for you (and no-share doesn't feel too punishing). That's fine, you are welcome to play no-share games.
Idk how to sugarcoat it. In a total beginner game literally nothing in the game feels impactful, you can enter a 1v1 5 minutes late and still win. Likewise in a 1k rating setons u can probably get t3 air at 12min and be fine (just guessing here) whereas in like a 1500+ game if you don't have 10min t3 air your entire team instadies. In a 1800+ mapgen I still constantly feel like people get away with murder, but that's how it goes. At every stage the margin for error grows smaller. So yea, it's not exactly surprising that in low rating games things such as losing an acu feel not that impactful.