just curious how the different tools the community has made stack up
Mapcomplete also offers filling info about existing POI, but you can filter on specific theme (Drinking water, sports) or very specific theme (etymology) or even your own. There's also an UI to add new POIs; I don't think it's possible with StreetComplete.
Either way both are great.
You can do it in Things and Places layers (layers can be enabled by tapping circle in top-right)
MapComplete has multiple in-depth layers, while StreetComplete is more general.
StreetComplete puts more focus on being usable out-of the box for newbies, while I would describe MapComplete as having focus on usability but allowing deeper dive in specific topics.
(disclaimer: I helped with developing StreetComplete)