I could not open elements on many sites after installing uBO
Then please report these filter issues to filter list maintainers, otherwise they will never be fixed for the benefit of all. Other blockers making use of the same lists will suffer just the same, this is not specific to uBO.
The default set of lists in uBO has been carefully selected to be optimal, best level of blocking for least amount of breakage, to ensure people can install uBO in an install-and-forget manner (contrary to your "not plug n'play" claim), whereas other blockers do not offer this pro-user interests approach, you need to configure them after installing them.
uBO acts according to content of filter lists, including filter lists used by other blockers (i.e. EasyList, EasyPrivacy), so if these lists cause issues on some sites due to false positives, it's best to report these issues to filter list maintainers so that they end up being fixed for all uBO users, and for all other blockers making use of the same lists.
If people uses uBO in a non install-and-forget approach and enable more filter lists, this can lead to higher likelihood of site breakage, the documentation warns that enabling more filter lists can cause higher site breakage, this is true for all blockers.