There's definitely a chunk of the real estate bubble that is actually real...it's being fueled by inadequate housing supply built. Esp for starter and middle class homes. So much of the construction has been toward the higher income end of the spectrum. They get better margins there and all those middle class developments going belly-up in the 2007-2008 crash spooked a lot of developers so they were slower to come back to building those units.
But there's definitely an artificial part of the bubble too. The very low supply isn't all due to lack of construction. A lot of it is due to people just not selling right now which started during the beginning of the pandemic. Once more sellers finally decide to test the waters, there will be a natural correction.