The macOS built-in TTS (dictation) seems better than all the 3rd party, local apps I tried in the past that people raved about. I have tried several.

Is this better somehow?

If the 3rd party apps did streaming with typing in place and corrections within a reasonable window when they understand things better given more context, that would be cool. Theoretically, a custom model or UX could be "better" than what comes free built into macOS (more accurate or customizable).

But when I contacted the developer of my favorite one they said that would be pretty hard to implement due to having to go back and make corrections in the active field, etc.

I assume streaming STT in these utilities for Mac will get better at some point, but I haven't seen it yet (been waiting). It seems these tools generally are not streaming, e.g. they want you to finish speaking first before showing you anything. Which doesn't work for me when I'm dictating. I want to see what I've been saying lately, to jog my memory about what I've just said and help guide the next thing I'm about to say. I certainly don't want to split my attention by manually toggling the control (whether PTT or not) periodically to indicate "ok, you can render what I just said now".

I guess "hold-to-talk" tools are for delivering discrete, fully formed messages, not for longer, running dictation.

AFAICT, TFA is focused on hold-to-talk as the differentiator, over double-tap to begin speaking and double-tap to end speaking?