It's not unusual for some rims to pull through at the spokes with cracking/splitting. Can't be repaired. Some 1980s-early '90s hard anodized low profile lightweight rims seemed more vulnerable.
I had two rear wheels crack the same way last year, both from late 1980s road bikes: one, an Araya CTL-370, one of the lightest clincher rims ever made; the other, a Wolber Alpine Super Champion, made very similarly to the Araya CTL-370 but slightly heavier. And both wheelsets demanded frequent truing. That's just the tradeoff for such lightweight rims intended for climbing and competition back in the day, before carbon fiber. Both were noted by users for this kind of failure years ago, so I was fortunate to get this much use from them.
Yeah, spoke tension matters. But some aluminum rims seem much more durable and need less maintenance. I've since switched to slightly higher profile aluminum rims. Very low maintenance. And I'm not strong or fast enough to notice much weight difference (for me, supple tires and latex tubes matter more than rim weight).
Currently I'm riding rims like the Mavix CXP21 (21mm rim profile) and CXP30 (30mm) sorta-aero rims. They're heavier, but bulletproof on our increasingly terrible roads. I hardly ever see any resurfacing with proper smooth pavement anymore, other than the city's favored gentrified areas and high tax base wealthy neighborhoods. The rest of us get coarse chipseal, like railroad ballast glued down with epoxy resin. Brutal on lightweight rims and harsh tire/tube combinations.