Exactly my experience. There's so many hypothetical fixes on the Internet, some seems to improve intermittently and temporarily, some seems to not work at all. But toggling Bluetooth seems be able to get a reaction from the OS at times. It felt like a ritual and I'm praying to the OS god.

Then one day a fortnight ago, I chanced upon another solution. Some people are speculating that because the WiFi signals is clashing with Bluetooth signals as they are both in 2.4 GHz, its affecting the WiFi. I was using Apple Wireless Keyboard & Touchpad. I have friend who had similar setup who seems to have the same issue.

So the next day, I spent 464 USD just to upgrade my router, get a wired Keyboard and a wired Mouse.

I have definitely splurged on these hardwares but at this point I am so frustrated and desperate that I need to make sure any hardware issue is out of the question. These are the only variables I can control, anything else felt hopeless.

I then jumped on 5 GHz WiFi and stop using bluetooth. My WiFi situation have improved a lot since then. Not perfect, but not un-usable.

The point is that I could have saved those money. To spend so as to fix a bug felt so Window'ish. It use to just work, and glitch are bearable, now I always worry of upgrading.

Anyway, those money could have went into buying Apple stuff.