Until 1961 suicide was a crime, the word ‘commit’ was used in this context which is why it’s an important we consider the language we use.
There is a slight difference. But significant. Someone can “commit to suicide” as in they will not stop attempting to end their life, they demonstrate ideation and each attempt is a serious, committed attempt to take their own life.
Yes, commit can mean different things but when coupled with the loss of a life, it will often be associated with a criminal act.
Additionally, the word “commit” implies that suicide is a choice. This is not always the case. Mental health issues and perceived pressures can often make someone feel like they have no choice. The last thing we want to do is make a survivor feel “well, you chose this”.
So it's more about a modern approach and inclusive terminology than pedantry. Fair enough.