This surprises who, exactly? Trump has been a egomaniac moronic blowhard since he became a celebrity back in the 90s (might even have been the 80s). Anyone surprised by Trump being Trump really needs to look inward.
Trump has two talents: understanding the zeitgeist (reading the room) and self-promotion. Classic con man. That is how he got elected in 2016 and may get elected in 2024.
What "the experts" refuse to address is: When a huge portion of the US electorate knows Trump is a lying sack of shit, why would they still vote for him? How bad must the other options suck for so many people that they are willing to vote for Trump?
Trump is filling a need that is VERY clearly NOT being filled by other politicians.