The talking heads are all beating the drums for impeachment because, wait for it

[StarfishSaver]

28. An impeachment proceeding is not the same as an investigatory process

A very rough analogy would be:

Mueller investigation + hearings by various committees looking into the wrongdoing described by the Mueller report along with other illegal and inappropriate activity not covered by Mueller (e.g., emouluments, tax evasion and fraud, money laundering) = a police investigation

Impeachment hearings and vote = presentation of evidence to and criminal indictment by a grand jury

Senate trial = court trial by jury

Although the Mueller report on its own contains enough information to convince some people that impeachment and removal are warranted, the House owes it to the country to put together a rock solid case AND to uncover and document as much as possible. That can't be done on the impeachment process and can't be done solely by the Judiciary Committee. That information must be gathered and then presented to the Judiciary Committee, which then takes it through the impeachment process.

Also, the American public is not there yet, at lease not in the numbers needed. Hearings outside of the impeachment process - hearings designed to gather information, not simply to push toward impeachment, which many people would just see as a partisan, outcome-determinative activity - are necessary for the public to be moved toward supporting impeachment.

Everything the impeachment supporters want can be accomplished without starting impeachment proceedings immediately: hearings, testimony, new information, exposure of Trump's crimes, etc. But initially, it must be done outside of the impeachment process if impeachment is to actually work.