Hi everyone 
I am setting up from scratch my /e/ os on Motorola Ocean phone. After all preparation I started to think, what is a better solution to OS backup:
or
I would like to receive backup of all system settings with sms and Signal messages, however I am not sure which solution is more convinient and reliable 
Regain your privacy! Adopt /e/ the unGoogled mobile OS and online services
moto ocean has an S release, Android 12 - from Android 13 Seedvault can backup more “relentlessly” and backup App settings despite them wanting to opt-out of any local backup.
Until there is a A13 release or the fake-“device2device” feature backported to A12, you’d need to reach for the twrp backup solutions to have a “high fidelity” backup.
Checkout the long [HOWTO] Backup and Restore Data on Android Devices thread (reading bottom-up I guess?) what users currently go for
Regarding backup with help of e os account, does it contain sms messages and contact list?
it has your contacts by nature of carddav, but not your sms messages.
You can enable seedvault and choose the murena cloud as target (needs the nextcloud app though), then your sms messages will get backed up I think.
The current Seedvault packaged is a bit long in the tooth but I think you can use it. It won’t include all app data so that is a caveat. In Android S you can to Settings → Backup → Seedvault. It’s not hidden anymore