Please correct me wrong but for a better form of sandboxing, I would recommend something like microvm and the bottlefire thing which was recently shared if that might pique your interest as I found it to be interesting and then using it with something like https://github.com/Zouuup/landrun
There is also tinykvm and other projects too which can simply take a binary and run it and I think that maybe developers should also try out all the different sandboxes and different things just for understanding as well I suppose too. To me, I really like playing with different form of sandboxes or such technologies in general.
Also do note that I am not sure if bottlefire provides sandbox/isolation by default as they mention Sandbox with Landlock seperately so I am now a bit confused if they provide sandbox by default or not as I previously thought it might have.