In the olden days, T7 was excellent due to it's fuel economy (yep, fuel was expensive these days).
Full tank in T9 costed around 700.000 iirc. When you had a good trade run (normal trade, there were no shortcuts in the first couple of months), you had to deduct that from the income.
Full tank in T7 was 50k. So you could compensate lousy cargo space with cheaper fuel. It had it's niche.
Yes, that's the issue with the Lakon Type 7 lacking a niche
Back when ships had higher maintenance and running costs, the Clipper cost an arm and a leg next to the Type 7 so you could see the benefits of each.
The Gutamaya ship was fast but costly to run and repair, and has short legs, the Lakons where cheap to run and repair, and had great fuel tanks
It added to the Shipyards different styles and aesthetics when their running costs matched that image
I have been using mine for the last 2 CGs, the Bridge looks brilliant in VR.
I have been using mine since the Lugh Conflict, running blockades into Khaka and have event taken her to the Core and back.
With Engineers tried Grade 4 Clean drives (saved the materials for the grade 5 for my Sidewinder), grade 5 FSD and a Grade 1 Low emissions PP (with a side effect of Positive MW gain) makes her quite a comfortable fly