The value of a house rarely decreases, yes. However the rate of appreciation can, and has, fluctuated over the years.
If historically, you have seen an asset appreciate at 4%, over the past 30 years, and then in the past year it appreciates by 18%, do you
A. Hop on in the hopes that historical data is irrelevant, and this asset will continue to appreciate at significantly higher than what we have seen in the past?
B. Anticipate that in a return to the norm, future performance will underperform other assets for a while, as market dynamics correct the aberration seen in the previous year?
If the answer is B, then if you buy this year, then you're relatively fukked if you're relying on asset appreciation over the next 30 years.
Now, if financial return doesn't matter to you, and you just want to buy, and you can afford a property easily, sure, go for it.
But if you're looking to buy a house because you think house prices will continue to appreciate at current rates, and they will not level to historical appreciation rates, then...