Then why hasn't anyone been charged with any crimes?
Because the people cheating were beneficiaries of the election and were elected into offices that run the 'investigations' and they protect their illegal acts. One example is the Sect'y of State in charge of state elections, now Governor, set up the machine purchase and the cheat, and a County Clerk overseeing elections reported election fraud to the press. The SoS summoned the Clerk to an immediate meeting. The Clerk made a backup of her election machine before leaving. When the Clerk got back she learned the SoS and law enforcement had just been in her office and said the election machine had been tampered with. The tampering turned out to be the erasure of the machine's log files of signon access to it of the 2020 election, leaving previous elections intact.
Failure to retain election materials for 22 months? Check.
Unlawful election. Check
Not knowing the Clerk has the data that was erased on her backup? Priceless