So ...

We are going to use a handy plugin called mb.YTPlayer.

Here it is:

https://wordpress.org/plugins/wpmbytplayer/

It's a quite small plugin (410 KB), but let's see the usual speed tests ...

Here are my results before installing the plugin ...

... and the result after installing and activating the plugin:

No more comments needed ...

So, let's see how it works ...