To me I don’t think it’s too late to buy bitcoin, simply because bitcoin is not yet at it ath yet. So someone can still buy an affordable bitcoin as it is.
ATH meaning all time high is a characteristics of the highest price points Bitcoin has achieved which is around $109k and it has nothing to do with your purchasing power since you can buy a fraction of it and not a whole Bitcoin making it much affordable especially with the idea and concept of DCA strategy that's is being talked about.