Completely agree, and am hopeful they will add the missing features and have some sort of "realism" update.

Basic things like the inability to manually set barometric pressure - there's no option in the G1000 implementation, you have to press 'B' on your keyboard and it just sets itself. Little things like that add up and firmly take MSFS2020 out of the "simulator" category... for now.

Some others have mentioned that MSFS2020 might be more akin to a platform, upon which content will be added over years and years. Some enterprising individuals have already figured out how to add helicopters, for example, while officially there's no support for helis by MS/Asobo. So, I remain hopeful.

I would argue that historically MSFS series has indeed been more of a platform and an ecosystem than anything else. It's predecessor Flight Simulator X also had quite shallowly modelled default aircraft, yet over the years third-party (mostly payware) devs modeled almost all commercial airliners in use today to a very high detail.

So, I think MSFS2020 will be a great simulator for those hardcore simmers who are willing to pay 50-150USD for a single aircraft modeled to a very high detail, just like they did in FSX days.

Yes, for sure the add-ons ecosystem will fill every possible niche. However if we look at X-Plane, we can see that having good quality default avionics can actually help add-ons makers, the two things are not mutually exclusive! Many 3rd party X-Plane add-ons improve on the default avionics rather than having to develop a unit from scratch (like it’s often the case with P3D add-ons). This means that developers can focus on other aspects (e.g. failures, systems, walk around, manuals) while reducing dev costs.