I love Organic Maps, but when I try to search, I think I find what I'm looking for about 1 out of 5 times.
Acastus-Photon (An online address/POI search for navigation apps) https://f-droid.org/packages/name.gdr.acastus_photon/
Edit: also https://github.com/organicmaps/organicmaps/issues/5891
Searching the schema works just fine, it's just hard to find typos and support natural language queries. Google set the standard for searching, we need to remember that we're literally comparing a volunteer project against the world leader in search who also has the money to employ a hundred distributed servers for every query versus the offline on-your-phone search of something like OsmAnd.
Borders is one of the few things that need to be different between countries (county, municipality, city group (Kreisstadt), city region (Städteregion), etc.: every country has a different hierarchy of subdivisions which OSM translates to numeric admin_level values). Some countries use the abbreviated street names like St. John St., others have the convention to expand Saint John Street. Different road types have different rules (is a tractor allowed on rural motorways? In Uganda maybe yes). These handful of things which you'll need to set per country are defined on the wiki, but 99% is the same. Particularly for searching where the name and POI tags like shop=x are the most relevant: after normalising the street name abbreviations, you're pretty much good.
The addresses in particular are heavily dependent on the country and region. And of course OSM is a subject for controversies and stupid edit wars as well, just like Wikipedia.
I'm not criticizing OSM, mind you - just explaining why it's hard to implement a good search in it; you have to constantly adapt your application to what people actually use in the map in different countries/language communities.
Also, in the same city, route planning (by bus) did not work. Which was a bit funny to me, when I lived there 10 years ago the city refused to make the bus data available to Google Maps, so back then it was Google Maps that also could not do route planning there.
I like Organic Maps, with its offline functionality it provides a layer of reliability that Google Maps is missing - and my phone has no Gapps anyway. But it's a pity neither search nor navigation is close to what Google can offer.
That is not huge problem. You can support just the most common schema. Except some rare cases it will not have real bad consequences (note: as OSM mapper I put quite significant effort into getting rid of some pointless duplicates, but I do not consider it a blocker for data use).
The problem is that making search working well with descriptive, incomplete, typoed, confused input is really, really, really hard. Google Maps search is the most amazing Google project for me.