I understand, it can be frustrating. But investigations take time. There is more to gathering evidence then just "Hey, lookie here we have a document!". You have to build a chain of custody for how that document was moved, who moved it, who authorized the move, were the individuals involved aware of the law, etc., etc. All issues that have to be proved in court.
Of course, there are some - that want the indictment rushed so that if there is any procedural mistake they can build conspiracy theories around it. Hoping the case gets tossed for a minor technicality and then they can claim "He was INNOCENT" (shades of OJ).
Hell in Georgia they are just hearing testimony from the 2020 elections for the FPOTUS trying to influence the vote count (phone call to governor). That was 1 count it ONE phone call. In this case we are talking over 100 Classified Documents and in excess of 10,000 pages of Presidential Records (Government Property).
WW