every other major global sport is not dominated by any particular race, then why only tennis?
First of all, I disagree with your premise. But to the extent it's true, the anser is ..... Money.
Tennis requires large facilities that require constant maintenance. Very few sports are like that. Golf, football, baseball, basketball, the required
facilities are inexpensive. The only sport that is much like that is gymnastics, for the same reason. Costly, specialized equipment. So it's only played a lot in richer countries, and the European and European-descended countries are the richest. No surprise that the non-White countries that do produce top tennis players are rich too. Japan, China, India.
There's also a regionality issue to it in the States. In Georgia, a lot of Blacks play tennis. In New York, not so much. One reason why? Money. In Georgia, there are a lot of public courts. There are a lot of public courts in New York/New Jersey too, but for a quarter of the year, they're covered with snow. So people who want to play have to pay for indoor court time. The average white household has ten times the wealth of the average Black household in the USA.
Tennis is great, but the cost of indoor court time is to the sky.