it is hard to learn. been to a 10 day vipassana retreat this year, and out of 100 hours of sitting, i've spent maybe 5-10 truly concentrated, and we're talking perfect conditions, with some prior experience
the most difficult part in my opinion is getting the reference point for how meditation should feel like - you can spend years doing what is breathing exercises, visualization, etc. never hitting that point. this is where Muse (https://choosemuse.com/) helped me tremendously
commercialization aside, the real question is about the value of guided meditation most of these apps are about. like, honestly i don't know.