There will be bugs. Lots of them. If there is no progress halting bug in the game someway halfway through the main quest, that will be miracle and I will question whether it is Bethesda game at all. All bethesda games are bugfests on release, but at least they give the community keys to the game and then we got unnoficial patches, that fix like thousands and thousands of bugs over time
Fallout 4 biggest issue was that it was just Skyrim with guns. And releasing 4 years after Skyrim, most people already felt the Skyrim fatigue by that time, me included. Starfield has at least that advantage it is not looking like carbon copy of Fallout/Skyrim formula, after all, it is a space game foremost and that can pour some new life into bethesda game design.