As you can see on BBO, the US Team Trials to select the team for Lille is progressing apace in in Schaumburg, Illinois at the moment.
For teams that did not gain the seeding points required for a bye (that is, 15 of the 18 teams), it is a long and costly event if you are going to win. They will play ten consecutive days of top-level bridge with about 50-60 boards a day. Given all the other days of bridge in the season, not to mention the target competition in Lille, a normal 'working' person would not be able to take the amount of time off work necessary, so they are excluded from the process.
The entry fee for the event is $360, but on top of this there is a $300 session fee per day. So if one, or two, of the 15 teams reach the final, the cost of winning the trials (or, worse, losing in the final) will be $3,360. This strikes me as quite a lot of money and about double the cost of playing at one of the Nationals. Nothing to some of the wealthy sponsors, of no concern to the professional players, but good amateur teams are not going to show up.
Of course this is the American way and, with so many professionals and sponsors, unlikely to change. But those who extol the virtures of this approach for other countries might like to consider whether this is fair for all.
