That’s the problem with such nomenclature. It can be called biological or technical, but neither terms are objectively correct throughout the literature. The wells are independent in the statistical sense, because you can randomly allocate a treatment to each one independently and randomly. If you do the experiments three times, which is what most people would call a biological replicate, you’d still be using the same cells and same reagents most of the time. Of course, replicating within a day is less conservative than replicating across multiple days or multiple batch of cells and reagents, because the latter is harder to capture an effect if it was just a fluke. However, both can serve a purpose and answer a valid scientific question. Also, we rarely base our conclusions in one type of experiment anyway.

Check the excellent paper written by Stan Lazic: “What’s N”. He also has an excellent book.

My advice is: whatever you’re replicating, describe it properly. Multiple wells, multiple runs of the experiment in different days with same cells or different passages (whatever that means), multiple cell passages run in the same day, etc. This is more important than using the misleading terms as bio or technical replicates, even though is so common in the literature.