Idk, ~five years doesn’t seem like a long time with regards to CPUs. I had my Ryzen 2200G from summer 2018 to this January, and I would consider my purchase of a cheap Ryzen 3600 to be a bit premature (and it was definitely an impulse purchase). And it also means that the CPU sticker became outdated pretty soon.
I have no clue what’s meant by “without download”, but this app just uses web assembly to inspect the archive in the browser. The sandbox they talk about most likely refers to the browser sandboxing.
So it pretty much boils down to “risking running malicious code is fine, because this app as a whole is treated as malicious by the browser”.