I don't grind neither. The game just isn't fun to play anymore with engineers.
If the game was fun before engineers, why has it stopped now. You don't need engineers to play the game. I have very few engineered modules which I think the only part I did grind for was the mining part to open one up. But even that I could of done it in such a way that it would have been a lot more fun. But I am not complaining about that as I subjected myself to that. Getting a few engineered modules is no grind. It is, if you want to do them all at one time, but the game never forces that on you. That is a choice. I do the odd upgrade every once in a while. I enter the odd USS when traveling. I fight in combat zones and res sights with minimal engineered modules and I am not a great pilot.
All I have done is do some slight changes in how I play. I scan a few wakes every once in a while when leaving a station. I try to scoop stuff when available.
Do a planetary scan missions. When down there blow up a few rocks every now and again. The materials rack up pretty quickly. Also you get materials for rewards too.
You do not have to go through the engineers all in one go.
Play virtually the same as you did before but just add a few extra things to do and it will not feel like a grind.
But if you go in to tunnel vision mode and do nothing else. Then yes, it will be a grind. But that is down to the player.
Now guardian ruins on the other hand. Well they can be a grind, but only if you engage in them. As none of the items are needed to engage in any other content, I see no reason to grind them out. I may visit the sites for the experience though.