One of the most popular reasons men choose suits over tuxedos is personalization. Selecting the more traditional “Tuxedo" as a rental sometimes leaves the wedding groom and bride feeling not as special or unique as having a custom suit made special for them.
Other reasons men are leaning towards suits can arguably be the following:
1) They can use them for another day.
2) They offer more styles.
3) They can be purchased as well as rented.
4) They can be more accessible.
5) They can stand out from the groomsmen.
In addition you can personalize your suit with custom embroidered signatures of your name and wedding date etc…
People have changed the way they talk about Tuxedo’s in the sense you might hear a tuxedo referred to as a tuxedo suit or formal suit instead of the conventional description of tuxedo or formal wear.
Wikipedia has a hard time differentiating their definition of suits and tuxedos using almost the same verbiage for both. So it seems natural to also have people combine the meanings as well.