It's 100% about convenience. They offer nothing more than you picking up your own food. Plus they ship as much packaging as food so it's probably far from being the most ecological solution.
But yes, the packaging is insanely wasteful, not to mention the ecological cost of shipping itself.
I definitely cooked more often when I had a HelloFresh subscription. And when I do cook now, the variety of things I make is much smaller.
This is more of a problem with how fucked American supermarkets are and how much food wasted is generated not just by too much being packaged. I go out of my way to shop at Asian supermarkets because at least I can buy alot of produce individually and not massive bags of shit that'll spoil before I can eat it like American supermarkets push.
But as someone who is reasonable acceptable at cooking, I do like the idea of something where I can get outside my comfort zone.
In the same vein, Blue Apron and Hello Fresh, I'd imagine, are there to expand your horizons in terms of culinary options. If it's just me going to the grocery store, then I'll just get for any old recipe I know.
They both remind me of a Danish company, Aarstiderne, which has been around since 1999, where the sales pitch is fresh organic vegetables with curated recipes by chefs every week. Particularly in 1999, when organic vegetables were harder to come by - even in Denmark, it made a lot of sense. Now they have so many different subscription choices (that offer different kinds of culinary experiences), that it's akin to picking the channel on television, but letting the programmers pick the programmes.
That's the appealing thing to me, it's actually less the convenience.