>If they did something illegal why weren't they charged years ago?
Because the Microsoft/OpenAI deal was not even a thing "years ago". (Duh.)
That aside, I will answer the charitable interpretation of your question by sharing a bit of knowledge about how the law process works (in the Western hemisphere).
To put someone who committed fraud in jail, law enforcement conducts an investigation to gather evidence, leading to criminal charges filed by the prosecutor.
The defendant is arraigned, and pre-trial motions may be filed before the case goes to trial, where both sides present their arguments and evidence.
If found guilty, the court imposes a sentence, which can include incarceration, restitution, and fines. The defendant may appeal the verdict.
This is a very simplified overview of the whole ordeal, which could go on for years and years depending on the complexity of the case.