Which I use for years, and just because of lack of a better alternative (minimal, OSS) I actually quite "hate" it.:

It has no rules, like "Allow a file with THIS name on THAT path", the biggest complain of every simplewall user is its biggest flaw and annoyance: It asks you a million times to allow or deny the "same" app, after its checksum changed. So all the Windows apps that auto update always pop up again and again.

A coding agent autonomously compiling and testing an exe with network access is impossible. I have to turn off simplewall, because it would constantly block the executable after recompilation.

I'm a simplewall user and what you describing is not my biggest flaw or annoyance - I simply don't upgrade windows (why would calculator need updates??) and after clicking few denies, its get very quiet. Been this way for 2 years now on Win 11.

Personally I like getting the security updates even if I have a firewall.

Even among simplewall users I bet the vast majority install OS updates regularly.

I also easily recommend this one. And OpenSnitch on linux seems to be doing the same job, though the interface can be less friendly.

Simplewall is quite terrible, IMO. They still haven't fixed the painfully slow fuzzy search functionality for firewall rules.

My go-to for years on all my Windows PCs. I can't find anything else that's as simple and powerful. The only annoying thing for me is having to use Windows Store apps (like WhatsApp through msedgewebview2), but everything else is super easy and straightforward.