Mane had a bad season before his last, people forget, and no one was saying he wasn't stepping up.
It is not a problem when one player has bad season, Salah more than covered for him that time and both Trent & Robertson were unstoppable. When you have the results, players aren't under that kind of scrutiny. This season most Liverpool players are under-performing and results show it well. Then media starts taking them apart one by one since that is what sells the papers

Nobody would talk abut bad defending if Liverpool outscored their opponents with results like 6:3, they would be speaking about playing football for supporters and always looking for a goal more.
You made an excellent point Trofo, and if you recall, when Liverpool began showing signs of disorientation at the end of last season, as well as a lack of motivation on the pitch, In addition to mane, whose departure has also affected Liverpool this season, it may not have been due to him.
As a result, Liverpool has a lot of things they need to fix before they can get things back on track again.