There are several geocoders available for OSM. To say that "the database is inconsistent [and] contains many errors", and then back that up solely with a criticism of one piece of client software, makes no sense.
I've backed the statement that OSM contains errors by saying that there are duplicated addresses.
I've backed the statement that OSM is inconsistent by saying that sometimes streets in OSM contain full name and sometime only most important part (and that makes Nominatim unable to search for addresses).
I agree, we started looking at OSM's address data sets only to find them pretty sparse. For the areas we investigated I'd estimate around 5% coverage from community efforts. Made me wonder why nobody's done something stupid like grab the files from http://openaddresses.io and create a reasonable starting point? But that got me thinking why even bother with Nominatim vs just throwing all that data into elastic for better fuzzy searches or match.