I've never played a Bethesda game and unfortunately Starfield isn't going to change that (at least in its current form). Based on gameplay footage and reviews I'd rather just stick with No Man's Sky. NMS seems to do the space exploration better and can already scratch that itch for me. The loading screens and fast travel are off putting enough that Starfield doesn't seem worth my time. The only feature that draws me to the game at all is the ship builder.
After fallout 4 it went downhill so try any of the previous games depending on how much dated graphics bother you. With mods most of the older games are very enjoyable.
Bethesda has been going downhill ever since Morrowind, to be fair. It's just that with each release, the number of disgruntled people have been growing, and with Starfield its finally the majority opinion.