Sc00byUK I run most of my buildings as much as I can and have them reasonably well upgraded. I use more fish than the pier produces...
And that, I believe, is the issue ... to upgrade or not to upgrade?
I think it's a vicious circle - if you want to upgrade your port, you need more materials, so you have to increase your production capacity to make them (or upgrade your destinations aggressively), which in turn means making more Concrete .... and then you need more Fish to run them - and so on.
Up to a point, yes, you need to upgrade, but once you start needing millions of tons of Stone, I think it's more efficient (and easier) to manage with what you've got 😀
By way of explanation, I used to upgrade everything as soon as possible, but I realised after letting my Houses fall behind that I could manage with what I had. I simply extended that approach to almost everything and I'm still making progress.