Do engagement groups really boost your engagement ?

Hey guys,

I used engagements groups for few months it boosted my engagement at the beginning but a little later the engagement started to decrease. I talked with someone who told me that engagement groups kill accounts. So I tried to stop and I've seen my engagement drop af.
Even lower that before I started to use these groups (when I had ~7/8K followers less)

Is it normal ? Do you guys use engagement groups ?

Thanks