Lace-ups are the most acceptable styles around the world for businesswear. Dressiness of lace-up mens dress shoes styles starts from the smoothness of the leather used (rough grain leather are less dressy), followed by the type of lacing (blucher is considered more casual than balmoral), and finally the amount of detailing (the more details like perforation, the less dressy).
Slip-ons or loafers are the other option for mens dress shoes styles that has been regarded as the less formal dress shoes. But we should not assume that all slip-ons are casual. There is a particular category of loafers which are meant for the evening black-tie affairs.
Besides its ease of wear, it is also a versatile pair of mens dress shoes that can be clean in its cut with minimal detailing and suitable for both casual and formal wear. One of my favorite mens dress shoes styles. It is simple and yet elegant with an exceptional clean cut. The Plain-Toe Oxfords can have both the blucher lacing and balmoral lacing.
A Plain-Toe Blucher Oxford definitely has a less formal look compared to the balmoral lacing ones.
The Plain-Toe Balmoral Oxfords work well for both business wear as well as formal occasions that require a dressy pair of dress shoes. Its popularity lies on its versatility, elegant, and firm design that draws so many men to it.
The Plain Blucher Oxfords can also transform into a casual style suitable for business wear. The use of rougher grains of leather will make it look less dressy, and examples would be using crocodile skin to create such a look.