That's on Apple not on emojis.

In the Windows 11 emoji picker it works like this:

1. Search "kissing". See two generic yellow people kissing. Notice a blue dot in the bottom right corner.

2. Clicking the emoji brings up previously used versions of the kissing emoji, with a + button.

3. Clicking + brings up a dialog like I described previously. Two generic figures at the top, then a row of skin tones.

4. You can click on each generic person and choose a gender, then select a skin tone. You can do this for each person in the group.

5. Click done. This emoji is now in your default emoji list and you won't need to recreate it again.

That seems like a lot of effort when you could have sent <kissing-lips>, <kissing-cat>, <kissing-face>, <heart>, or any number of other emojis, which is what my point was.

You still can! People who want more customizations can do so too. Plus it only takes the initial setup per emoji at least.