My father started his self-hosting journey with a similar need. He went with Piwigo (https://piwigo.org/ https://piwigo.org/) that seems to fit his requirements

My father started his self-hosting journey with a similar need. He went with Piwigo (https://piwigo.org/ https://piwigo.org/) that seems to fit his requirements. Not sure I would personally pick that (PHP, documentation misaligned with my concerns...), but it may match others' criteria.