This wasn't how it was supposed to be though - each ship was supposed to have a different role - to some degree, and engineering allowed players to blur the lines too much imo.
I'm exploring in a Corvette, you're right that that wouldn't be as practical without engineering. I've taken a ship with a poor jump range & made it acceptable because meta is boring, sub-optimal is just a more interesting way to play. I'm still compromised on speed & handling compared to a smaller ship but those are compromises I'm prepared to accept for the sake of the kind of flexibility I want in a ship I spend a lot of time in. It can handle any RES or CZ, and can beat off the stream of Elite Anaconda NPCs that come after me when I'm near civilisation for some extra revenue. And hopefully survive a player gank for long enough to not lose the hull. I'm compromised on shield boosters because of scanners & heatsinks but I have an SCB & quite a bit of armour.
For the speed thing I recently fitted an SLF bay (they weren't a thing when I left the bubble) for fun & maybe scanning planet surfaces, I fitted hull repair limpets too.
But I'm still compromised by a 19ly standard jump range, a compromise I'm prepared to accept where many other Cmdrs wouldn't, even in the bubble. I made choices based on how I play, and if I'm not going to dock for a long time and I'll be stuck in one ship I want that ship to be able to multi-role to some degree.
I think any ship should be able to put it's hand to any task. It might not be the best at it, but all should be able to do the thing you want. And if you want to do a little bit of everything, that's easier in a ship with more slots, the size of those slots (or the ship itself) isn't so important.