Why is there two bands instead of three in my new apple watch series 8 box?

I am not wrong. There was a time when they came with three pieces. One for shorter wrists and an extender for longer wrists. Apple doesn't do that anymore and at the time of order, you choose the S/M or M/L and there are ONLY two pieces in the box. You got exactly what you should have gotten with your band.

From Apple Order page for a Sport Band:

Band Size

S/M

Band fits 140–190mm wrists.

M/L

Band fits 160–210mm wrists.

This is a user forum, you are not addressing apple here just fellow users

I surely only got 1 band in 2 parts when I ordered by apple watch 4g back in the day

you can try contacting apple Support ->  Get Support (apple.com)

and or give them feedback -> Product Feedback - Apple

You get a watch and one band, which based on what you bought is the Apple Sport band comprised of two parts, one for each side of the watch. Why did you think you'd get three bands?

You are very welcome. Enjoy your new watch!!