Boruto Volumes are selling 17k behind Super, but both are being outsold by newer series like BnH, Neverland, etc,
Boruto sells like 200-400k per volume, Naruto sold like 1 million. The first two Boruto volumes added up to about 900k, or almost 1mill. I can't remember.
Although I think the series overall gets its best $ from merchandise, DVD sales, etc.
The Naruto Anime never did well in Japan, and I shit you not, the Naruto v. Sasuke battle got the lowest percentage of views despite them actually advertising it a lot. While shit like Shinden Arcs got more attention. No idea how that shit works.
Boruto's the same, low views compared to other popular shows on. But nothing worth caring about in terms of 'cancellation'.
Sequel wise it's pretty much just a few numbers behind Super. Most of the popularity for these series in the West anyway, so as long as the community exists, the market will stand.