Major League Rugby is far from the top rugby league.
England's 10-team Premiership, France's Top 14, and the United Rugby Championship (16 teams from 5 countries) are the top leagues. The best club teams in the world are in France, England, and Ireland. The economics of pro rugby are tough. Major League Rugby is down to six teams, and in 2023 three of the top England Premiership teams went bankrupt and folded, and these teams had been successful for over 100 years.
The irony is the US national team players are not good enough to play at the top levels in France, England, and Ireland, and Major League Rugby doesn't pay enough for the US's top players to commit themselves full time to the sport. During the last World Cup qualification, the US team lost to Uruguay, Chile, and Canada, then failed to make it out of a losers bracket featuring Hong Kong, Portugal, and Kenya.
Some pundits have described the US as rugby's sleeping giant. I'm not seeing it. When FBS schools offer 13,000 or so football scholarships to American high schoolers, and the best players now get paid, not many US youngsters are going to take up rugby in place of football.
All that said, I enjoyed playing the sport and still watch it. Plan to be in LA in 2028 to watch the Olympics and will attend some World Cup games when the US hosts in 2031.