I fully take onboard the other comments about cash grabs, incomplete etc and often agree. It's very frustrating indeed.
But I was also thinking about some of the things which you have mentioned. For small developers it might be the only way they can get funding and bring titles to us, which I find can often be far better than AAA stuff. This War of Mine is one such example.
I think your comment about developer history is key. If they are doing a cash grab or constantly fail on their promises, then hopefully they will be called out for it and not be able to repeat.
Sorry, my post may have come across as only negative. That's not the case.
The benefits clearly do exist, above all the point that it can enable the financial wares for a new company to develop something without having money in their pocket that they've been given by an investor.
We can all think of bad examples very easily.
My view on a good example is Eagle Dynamics and DCS. Some of their aircraft modules stay in Early Access for years and can look like they'll never get finished. A classic example is their Mosquito, which is very flyable, but still missing it's AI navigator capability.
However, that's a pretty short term view. I've been playing DCS for 9 years now, and yes, they appear to be unbelievably slow at delivering certain things. Making up for that, they do seem to eventually get there and what they deliver really does hit the mark. For example, their F18 was released in 2017. It's only now been given it's Data Cartridge and even that is only at an early state. From first glance, sounds like a disaster waiting to happen. In practice, in parallel they've delivered several new terrains, a number of other aircraft, a move to multi-core for the game engine, multiple updates to the graphics engine, and the data cartridge has been built in a modular fashion, such that the technology will be available for a number of other aircraft (e.g. the A10 and F16).
Without early access, ED probably couldn't have delivered what they have. In addition, we as players have assisted by acting as play testers, enabling them to further refine some incredibly complex models. I find it incredibly amusing that CIG thinks it's OK to create some large by still make believe ships, that probably having nothing like the system complexity of a DCS aircraft and charge such that ridiculous sum.