I will get downvoted for this but a Synology Nas is simple and does 90% of what google will do. They also have their own DDNS or you can use whatever you like.
Downside is tou have to buy their hardware. Unless you do the Xpenology route.
Been using a Synology NAS for the past year for automatic photo backups. Take a photo, it gets copied to my drive at home so long as there's internet access available. No issues so far. Turned off my backups to Google.
3: Raid 5 setup with 2 unused drives and setup to automatically spool up and recover if one of the drives starts failing.
2: off-site at the father in laws house (using a Xpenology super tiny PC and an external drive)
1: Monthly Backblaze
While there is risk, it's def safer if not safer than Google drive.
It's a dual drive redundant setup. Unless something catastrophic happens, I doubt both drives will go out at the same time. I could do an offsite backup as well, but just haven't.
The number of redundant drives actually doesn't make much difference, but it does "help". Instead of picturing individual drive failures, picture a house fire.
Also picture the next step after one of the drives fails -- you'll be copying all of that data off of your 1 good drive, putting a lot of stress on it. That drive is likely from the same batch, same age, etc. as the failed drive. The likelihood of your good drive failing during the recovery process is higher than one might like.
I have a Synology NAS, and while their Synology Photos is really good, it's no match for Google Photos. It's not their fault though, any self-hosted solution is going to be harder to share photos and do collaborative albums and such. And Google Photos image and face recognition is just not matched. I backup my entire photo library to Synology Photos but most of them are also in Google Photos for ease of access and sharing.