I'd say that the it's a 'dying fad' or 'emo took its place' is true as far as mainstream attention and highschool trends go, but in any population sizable enough to host a niche culture, people collect at the margins...
Yeah, most of the 80's and 90's goth kids grew up as an inevitable passage of time might forcast, but not all of them grew out of things they enjoy. I'd say offhand I know about 40-60 people, locally, who would self identify as goth, or being sympathetic to the style/scene. Most are mid 20s to mid 40's. Most dudes white collar professionals in tech jobs. Most ladies tend to work in tattoo parlors, retail, online business, etc. They make enough money to support about 3 to 6 active subculture bars in the city any given year and between personal interest and DJs, support the business of a (sub)genre(s) of music and it's artists / labels.
I'd say the subculture leans more on DJ nights and nightlife clubs than touring band shows (moreso than punk or metal), but in metropolitan areas of North America and Europe, festivals draw large crowds and prominent acts tend to bring more sub-culture-ites out of the woodwork than the regular barflys.
I live in a city with about 3 million people. The goth scene is proportionately very tiny, but for the ebbs and flows of activity, it's never truly disappeared; just passed from obscurity into the lens of mainstream focus and then back into obscurity, over 30 years or so.