We know that the team working on Elite is much smaller than 100. We know that the majority are working on New Era and, since that hasn't been delayed, we know that they continue to work on New Era.
We know that FD pulled out all the stops for Update 2 Patches 2 and 3, they probably pulled in people from other teams, and that didn't go so well. A small, knowledgeable and focused team can get more good work done per person-hour than a huge team with no experience of the code but they can still only get a certain amount done. Twenty people cannot do the work of a hundred. If you give them too much work then something has to give, and it's generally the old bugs and general robustness.
There's been a few comments on the forum talking about the lack of regression testing. A regression is when an old and fixed bug reappears in a new release. The classic way to get this is to patch one code branch but not another, but that is not very likely. Imagine you have an old garden hose. Every time you stress it, it springs a leak and you have to patch it. It isn't the same leak every time but the symptoms are similar. The hose is not robust. Instead of patching it each time, what you need to do is buy a new hose. But then you need to take the time and money to get in the truck and drive to town. If you need the garden watered now, it's easier to slap a new patch on it.
It appears to me that that is the situation Frontier finds themselves in. There are significant areas of the code that keep breaking. The coding isn't buggy, but it isn't robust either. As soon as it is stressed by a related new feature or an unusual circumstance, it breaks.
You can't afford the time to buy a new hose because you're building a new house next door for when the grandchildren are born and that's taking most of your time and effort. (You call it New Era, catchy name.) On top of that, your wife wants you to build her a new kitchen. But even when you move into the new house, you're still going to have to water the garden. You'll need to buy that hose at some point or the new house will feel as broken and run down as the old one. Maybe the kitchen will have to wait.