You know what, I was puzzled why our numbers are so different, and I think I fully believe you now. There are so many minute changes that you can make that can have a dramatic difference in how many writes the system generates. I was trying to drill down a little more, and -- oh my -- those numbers are extremely noisy. At times, I get only a few hundred kilobytes of writes and then it shoots up to megabytes and stays there for a while. Seemingly without rhyme or reason.
I start extra services, and the write load goes down; I stop them and it goes up again. It's infuriating to diagnose. But in the end it's just a normal Linux system. So, it shouldn't wear out an SSD this quickly.
I don't have a complete answer for you. But I have a few knobs that you can tweak and that might help. It turns out, that Proxmox likes to log all API calls to disk, and depending on what you are doing that could be almost nothing at all or a surprisingly constant stream of events. But honestly, I can't envision a scenario when I would need historic data. Storing the log of API accesses in RAM seems absolutely reasonable. They'll be there if I need them, and if a reboot wipes the list, then no big deal. I ended up mounting a "tmpfs" at /var/log/pveproxy I would think that this change should be relatively harmless for most users.
A more controversial change is also mounting a tmpfs at /var/lib/rrdcached That means you loose all your life metrics after a reboot and have to wait for a little bit for them to build up again. Personally, I couldn't care less. My hardware rarely gets rebooted, and while these stats are pretty to look at, I don't really use them for any important. I am fine with historic data disappearing when I need to restart the system.
If you run PBS, then there are similar tweaks. I believe the relevant paths are /var/log/proxmox-backup/api and /var/lib/proxmox-backup/rrdb
And, of course, if you really don't care about historic information, you can always edit /etc/systemd/journald and make the storage "volatile". But that loses you a lot more potentially valuable date. So tread carefully.
Now, for the million-dollar question, does all of this make a difference? And I honestly don't know. The readings are so noisy, I can't reliably tell. All I can say for certain is that I have historic S.M.A.R.T stats for the drives that show me total number of writes and total number of hours, and they don't look at all as bad as your drives. Sure, I have a bunch more disks to spread things out on. But even if I factor that into the math, the number is still much saner.