I am currently using a Sony RX10M4 camera with a Nisi close-up lens attachment.
It is a 'point and shoot' model (no detachable lens), so the lens attachment helps to zoom in on small organisms. With some support, I can take handheld shots of insects about 5 mm in length.
At the moment, I still find mirrorless cameras by Canon, Sony, etc. a bit too expensive for my taste, so I compromised by getting the RX10M4, which is considered one of the best P&S cameras with a huge zoom range, which is good for shooting all kinds of wildlife, big and small.