One thing I've learned over the years (and doing maintenance for shops a long, long time ago) is that every aquarium has a lifespan. Inevitably all of our reefs will come down one day or another. The most immediate 'threat' is always living situations, crashes and indifference.
It was often my experience that tanks would make it until a prized animal got too big and necessitated an upgrade. Regarding frustration 'quits' often people wouldn't immediately quit after a crash, rather they'd just do a slow fade out and talk about what the tank once was. Eventually tanks would just devolve into messes until a wife or girlfriend suggested it 'go away.' I was fortunate in my time to work on many that were 5 years or older- one one case 10+ years. Perhaps the best was a nondescript 90 gal That had become overrun with a bunch of mushrooms and simple acros. As long as we came in cleaned it every 6 weeks the tank just keep chugging along and was a great example of a 'grown in' aquarium. That is the difference though between having a service come and do the maintenance vs having the owner actively involved. Most people that do their own maintenance experience ebbs and flows in their motivation- which is to be expected- and its usually seasonal.
It's just my opinion but there's a 'filter' people must pass through when keeping an aquarium. It's basically just the sum total of motivation, consistency, and enthusiasm which will determine whether you continue to raise your ceiling and achieve your goals, or get stuck at a certain point and just spin your wheels. Probably very few people begin the hobby with a complete idea of what they want to achieve and so go from one thing to the next. Those folks, from my experience, are the type that go into the store and buy something new every week with little regard for how everything fits together in the big picture. When approaching the hobby that way its very easy to become complacent and 'settle' for middling results rather that pushing and developing their craft. Most of those aquariums have a few year life span at best. I also see the technology fetish as feeding into that demographic. All too often I seen an eye-watering equipment list but a non-existent understanding of basic reef chemistry. People that are able to get past these barriers tend to be in for the longer haul.
My current aquarium has been up going on 4 years- I set it up when we bought our house. However, the contents, including the rock structures date from 2011. We'd moved twice so I consolidated from a 120 to a 75 before arriving at the 220 I have now. I was fortunate that in both cases I was able to get the new tanks up and running before moving the livestock. In that way the aquarium I have now is very much the same as the one from 2011, the containers just changed and I got better at my craft.
My experience in the hobby: 1st marine aquarium 20 gal in 1995. Started working at the full service pet store in middle school and into high school 1997-2002. During that time I had a 55 gal which would give way to a Oceanic 120 in 2000. That tank would stay up while I was in college until about 2004-05 before my dad finally took it down. I restarted the 55 gal 2006 and it would go on till 2008 before I'd swap it out for the 120 gal. I also did maintenance for the aquarium shop from 2008-10. That 120 gal was up until the end of 2014 when we first moved. I had the 75 gal for about 2 years before we bought our house in 2016. I've seen a lot of changes over those years.
