As a designer this is a fascinating topic for me and I definitely think you’re pretty much spot on.
People have always been somewhat interested in style and design. Artistic movements go back hundreds of years. There’s also the marketing element, which arguably also goes back hundreds of years, ensuring the general public typically like to ’keep up with the Jones’s’. I’m also a believer that design isn’t as subjective as people think. Of course there’ll be preferences but it’s not accidental that some things are universally admired; certain sports cars, iconic furniture, buildings etc
I think the internet and social media have brought design to an exponentially wider audience to the point most of us, even if we don’t acknowledge it, know good design when we see it or at least have tastes and preferences. Before the internet, trends and fashions spread solely through broadcast and print media and word of mouth, or simply visiting someone else’s house, or things you’d see on holiday etc. These days, you can see the interior tastes of someone 5000 miles away with a few words typed into a search box.
It’s also meant previously ‘niche’ hobbies like coffee can easily spread to the point they become mainstream.
As a result, I think far more people put more thought into what goes in their house (Kitchen in this case), so the demand for different coloured/styled machines is there just like it is for cars or sweaters.
Whilst coffee is definitely having its moment in the spotlight, we must be 20 years into the ‘third wave’ so I do think coffee as a hobby is here to stay. I think the faddiness of it will pass, and we’ll see less of the influencer content as they move onto other trends. At the moment it’s self-perpetuating because it’s lucrative to spotlight trending topics.