Yes, there are goals like missions/ships/and just about anything in the game. Not sure what you are talking about. I don’t mind “sandbox “ but if to do anything in that sandbox means repeating something for hour on end ... then it becomes a grind which is quite an achievement to make a SANDBOX A grind. If it is such a sandbox, just give everything for free!!!!
But it's only a grind if you set those big ships or maxed engineering as your target. And even then you will eventually get them without grinding if you just play the game. Well, engineering will probably require a little grind, but even then not much.
I unlocked nearly all engineers to G5 and engineered my first 2 ships to mostly G3 or G4 with almost no grind, simply because I didn't rush to engineer everything the second engineers came out, just kept playing the game, and I soon had far more of most materials than I needed. Only had to grind when I wanted to build my Krait up to full G5, and by then I'd had years of gathering materials along the way, so it's taken me less than 4 hours of grinding to have everything G5 except my SCB, because I'm only Master combat rank. Selene Jean and Marco Qwent were the only unlocks which felt like grinding, the rest I mostly did a bit at a time, while doing other stuff in the area.
YOU DO NOT HAVE TO GRIND. If you really want to get big ships or G5 engineering as early as possible, that's entirely up to you. No-one is making you do it, except yourself.
You can deny that all you want, but when you find the game boring, and people like me who choose not to grind (mostly at least), still don't find the game boring, the proof is right there.