One possible problem is that generational earnings are a function of economic conditions. These may average out over a lifetime, but if we look at restricted intervals, it may seem like newer generations have less wealth even if they end up having similar overall wealth over their lifetime.

Leaving out boomer data from ~18-35 makes me a little more suspicious of cherry picking because that data could be similar. It may also show boomers gaining even more wealth, but if it's not available we can't know.