Most people are afraid (to some extent) of speaking in front of a large audience. Most people are not afraid of speaking with one other person.
However, a tiny fraction of our time is spent giving speeches or presentations to audiences of any size. Most communication happens in 1:1 conversations.
What's unfortunate about so much traditional "presentation skills" content is that it tends to apply primarily in these small group and large audience situations.
Yes, if you've got a series of high-stakes sales meetings coming up and you want to be ready, of course you want to develop the skills to succeed in those situations. The thing to understand is that developing these skills will take a lot of time, energy, and emotion.
Once you've done the hard work to improve how well you speak to groups, it would be nice if most of those skills translated to the massive number of 1:1 conversations you have in your professional and personal life.
Similarly, if you could improve how you communicate with one person, it would be great if that translated to speaking and presenting.
In my experience, this is the more efficient and effective method. You get to practice a LOT more, and with much lower stakes.
The difference between communicating effectively with one person or one million people is actually quite small. You may have heard the public speaking advice, "imagine you're talking to one specific person...."
It's good advice.
It's an even better training plan.