In my own personal experience, Nextcloud;

• Needs constant attention to prevent falling over
• Administration is a mess
• Takes far too long to get used to its ‘little ways’
• Basics like E2EE don’t work
• Sync works when it feels like it
• Updating feels like russian roulette

I dunno what you guys are doing that makes your nextcloud die without touching it. Mine runs happily until I decide to update it, and that usually goes fine, too. I don’t use docker for it, tho.