I tried vimwiki for a while but I found I used a tiny subset of its functionality and couldn't get it to respect my choice of syntax highlighting for markdown. It set me off in the right direction though.
The fact that it's _just_ a directory full of markdown files allowed me to easily migrate to my own home-grown setup that reimplements the three keybindings I actually used.
There's a community plugin called "Remotely Save"[0], which allows you to sync your data on s3-like services. I use this with Backlaze's 10gb free plan.
It took a minute to set up but runs without any issues for me.
I also tried Obsidian but I need it also mobile and I cannot define a storage path for my files.
I just like the freedom, minimalism and flexibility of vimwiki.