I'll echo TheSwavu's comments, this was already discussed. It was a conscious decision not to merge addresses onto other features on the map as part of the import.

Firstly there's different ways addresses can be mapped, as a lone node, on the building, on the landuse representing the lot, and the import took the simplest option leaving it to local mappers to decide the best option for each location.

Secondly, there is more risk merging to buildings, particularly in areas of high density, like narrow terraces the risk of mis-assigning address to the wrong building was too high so this was left to be done manually.

The notion that it requires cleanup to attached addreses to buildings in an opinion about how addresses should me mapped, it's also not incorrect for them to be simple nodes, so I reject that they require cleanup. You may improve if you like, but it's not required.