How to get super-tight MIDI playback?

What you found is a workaround. I’m suggesting that there must be an actual permanent fix for this because I’ve never heard of anyone else having this issue despite using Cubase for many years.

What’s definitely not going to help anyone is that attitude of yours. Since you’re looking for a DAW for grown ups, how about actually behaving like one instead of acting like a passive aggressive teenager over nothing?