serviceable
Good enough to work well, but not special or fancy.
Serviceable means good enough to do the job, even if it's not fancy or perfect. When something is serviceable, it works adequately for what you need it to do.
A serviceable bike might have scratched paint and squeaky brakes, but it still gets you to school reliably. A serviceable essay answers the assignment clearly without being brilliant. Serviceable shoes might not be stylish, but they keep your feet dry and comfortable.
The word suggests basic competence rather than excellence. A chef might describe a meal as serviceable if it tastes fine but doesn't impress anyone. A coach might say a player gave a serviceable performance: they didn't shine, but they didn't let the team down either.
Notice that serviceable isn't exactly an insult. It recognizes honest usefulness. Sometimes serviceable is all you need: a serviceable umbrella keeps you dry just as well as an expensive one. But sometimes you want more: a serviceable birthday present might disappoint someone hoping for something thoughtful or exciting.
If your winter coat is still serviceable after three years, it continues serving its purpose of keeping you warm, even if it's looking worn around the edges.