There are three categories: tax minimisation (structuring legitimately to minimise tax), tax avoidance (structuring legitimately but artificially to avoid taxes) and tax evasion (lying to evade tax).
Tax minimisation is fine. Tax avoidance is, in sensible countries, not illegal but ineffective: tax avoidance arrangements are void for tax purposes. Tax evasion is a serious crime.
Avoidance is not using the system as it was designed. It is using the system as it was not intended, creating totally artificial structures just for tax reasons. In a sensible society the taxman can just say "clearly artificial so I will ignore this" and if you disagree, well, see you in court.
Tax minimisation is fine. Tax avoidance is, in sensible countries, not illegal but ineffective: tax avoidance arrangements are void for tax purposes. Tax evasion is a serious crime.
Avoidance is not using the system as it was designed. It is using the system as it was not intended, creating totally artificial structures just for tax reasons. In a sensible society the taxman can just say "clearly artificial so I will ignore this" and if you disagree, well, see you in court.