Not good as it used to be

Im using line for 2 years and its way worse than the first 6 months of using it.
It crashes a lot, slow recovery of the upcoming messages, the quality of voice calls are terrible- even skype got better than line. Voice calls are having big noise in the background, my friend can barely hear me talking and I almost need to shout to microphone. Also it started to take up more memmory space. I understand there are some updates but actually it makes the app heavier and not really seeing any progress of fast & easy use of Line.
Even after delating my chat history twice, it havent speeded up.
I hope the developpers will try to fix those mention issues.

Greatns about LINE, v5.1.2