How to monitor basic .NET 7 app performance stats in production?

In old .NET I could use performance monitor to see things like GC collections or thread contention per app anywhere on windows

Now the performance counters not there or changed. I was told to use visual studio profiler to get basic metrics.

How do I do it on machines that don't have visual studio? developers aren't permitted in any form or shape ie must be available and feasible for a system admin

There is a number of dotnet CLI tools like:

• dotnet-counters
  > a performance monitoring tool for ad-hoc health monitoring and first-level performance investigation. It can observe performance counter values that are published via the EventCounter API or the Meter API. For example, you can quickly monitor things like the CPU usage or the rate of exceptions being thrown in your .NET Core application to see if there's anything suspicious before diving into more serious performance investigation using PerfView or dotnet-trace.
• dotnet-monitor
  > global tool is a way to monitor .NET applications in production environments and to collect diagnostic artefacts (for example, dumps, traces, logs, and metrics) on-demand or using automated rules for collecting under specified conditions.

They do not require installing Visual Studio on the machine (though they require SDK being installed).

Metric collection is a vast and quite complicated topic. There quite a lot of tools making life easier, for example prometheus-net or OpenTelemetry which allows metric collection including distributed environments.

Another possibility is to "manually" integrate this collection into the app via corresponding APIs or using other performance diagnostic tools