Not exactly "more popular" IMO, but at times can be "hotter" or more exciting. The ace(s), however, are typically heavyweights as I recall. And, for example, this weekend's "promotion" of Baretta out of juniors into heavyweights would be seen (again IMO) as just that: a promotion.
A lot of people have probably asked that question ... along with WHY is there a ...
It started out in 2010 as a sort of NXT-like belt, for youngsters & company outsiders. That quickly morphed into being an extra heavyweight division belt for NJPW. It has then become the closest thing they'd have to a sort of Hardcore Title ... of the 16 combined title reigns, 9 belong to a combination of Minoru Suzuki (the current) Hirooki Goto, Togi Makabe, Masato Tanaka (the inaugural), and Tomohiro Ishii (the most, 4x).
I feel like there's TEW mod that captures this relatively well right now so I'll lean on it for references, I'll give you the title and the prestige for each. Imperfect but it'll give you some idea I believe. With seven titles that are regular, you can't forget about the various annual tournament titles either, I'll
italicize those
G1 Climax - 95
IWGP Heavyweight - 90
New Japan Cup - 85
World Tag League - 85
IWGP Intercontinental - 70
Best of Super Juniors - 70
Super Junior Tag - 65
IWGP United States - 58 (*subject to the future, I figure 75 is the aim)
Super J Cup - 50
IWGP Junior Hvywt - 50
IWGP Tag Team - 50
NEVER Openweight - 45 (*I'd put it currently more like 50)
IWGP Junior Tag Team - 40 (*kinda floats up/down)
NEVER 6-Man Tag - 35 (*I'd personally put this more like 37 now)
I might group the first two almost side by side myself really.