The biggest problem with these open source maps is that there is no painless way to contribute updates.
The hard part is learning how to map well. The documentation is fragmented: There's a multi-language wiki with a lot of inconsistencies in the translations. There are dozens of mailing lists for various regions and sub-topics. There are IRC channels. There's a web forum. There's a subreddit. There's a Stack-Overflow-style Q&A help site. There are Youtube videos. And you can often find a different answer to a simple question in each of these resources! A little chaotic. But I wouldn't quite call it painful.
Creating an account is a pain point for some people. I notify companies and individuals all the time about typos, dead links, bugs, etc. In any instance where I am not an established user, the process halts when I have to create an account. I’m giving freely of my time and knowledge; the process for me to do so should be as close to effortless as possible.
Fair enough. And even fairer, if you're not an experienced mapper you may easily be able to spot a problem but not be sure how exactly to fix it. OSM has you covered -- right-click the map and select "Add a note here". Add a quick note with all relevant info. It won't appear on the map, but mappers who are working in the area will (hopefully) see it and fix it.
Not sure if Gnome Maps implements this functionality, but most phone-based OSM clients do.