Sometimes, that doesn't seem to matter all that much. I have a bunch of T8 replacement tubes, and like that I can replace them if the fail, but I also have some integrated fixtures that are super cheap and work quite well, especially for distributing light across a wider area than a 2-tube fixture. Those integrated fixtures have plugs (one with a 2-prong and switch, and a couple straight connectors to daisy chain) and yes, they are flimsy and light, but once mounted that seems pretty irrelevant. The ones I have mounted with their included clips were easy; the ones I put in my garage I just bailing-wired to the trusses:Avoid "Integrated" units, it just means if any part of it fails you need a complete new unit.
I feel like the T8 tubes are a little brighter but these integrated fixtures are much cheaper if you don't already have a T8 fixture in place.