The 25th Amendment requires the assent of the Vice President and a majority of the cabinet, a cabinet selected for loyalty to Trump. But suppose you get that. Trump will then assert that he is fit, in which case it takes a ⅔ vote in both houses of Congress (plus the VP and the cabinet) to block him. By contrast, impeachment takes only a majority of the House and ⅔ of the Senate—fewer member of Congress, and no involvement by the Vice President or the cabinet.
(There may also be an ambiguity in the text. It says "when the President transmits… his written declaration that no inability exists, he shall resume the powers and duties of his office unless the Vice President and a majority of either the principal officers of the executive department or of such other body as Congress may by law provide, transmit within four days to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office". Who is acting as president during those four days? If it's Trump, can he fire enough "disloyal" cabinet members to block a majority?)












